How to rule out a Spark Plug as your problem

[@electronicsNmore]

**ATTENTION: If you have any concerns about removing a hot spark plug from an aluminum head, then you can also remove the plug when it's cool and heat it up in a toaster oven to 300 Deg F to perform the "hot" test. Never file down or sand Platinum/Iridium tipped plugs. "Hotter" spark plugs have a LONGER ceramic nose, and "Colder" spark plugs have a SHORTER ceramic nose. Using a slightly hotter plug can prevent fouling if your rings are worn and allowing excessive oil to accumulate on the spark plug's electrode. Thanks for watching! **For GREAT deals(Usually cheaper than EBAY) on AUTOMOTIVE TESTERS & TOOLS, neodymium magnets, Fidget Spinners, electronics, drones, automotive tools, household items, phone accessories, locksmith tools, & much more, please visit the link below and SAVE IT AS A BOOKMARK on your computer or smartphone to Banggood for future purchases. (Your purchase supports my channel!) All Items: bit.ly/2cgYr14 Flash Deals: bit.ly/2cb6CZB *Try these money saving coupon codes: Double12 or BFTOOL or affiliate6 or elec or elec1 or measure or HDWARE2 or WELDTOOL or ask if other codes are available!

[@linusrautenstrauch9667]

electronicsNmore c

[@NitroGuyJH]

Lawnmowers now use suppression plugs due to the Delphi fuel injection systems on Kohler and Vanguard. Specifically the NGK bpr4es and bprm4es as well the 5’s too. If not the 5 volt reference in the OBC will act wonky and cause problems in the injectors as well as the coils. Just a little info on the subject :)

[@walterfosdike2163]

electronicsNmore "

[@garyswartz6512]

electronicsNmore 988

[@TRAVIS-L]

electronicsNmore what is the best spark plugs to use in a 98 ford explorer 4.0 sohc v.6

[@anthonywilliams4638]

Clear and articulate, no nonsense, good old common sense, no annoying hard rock or ricky ticky music to distract. Well done. Keep up the good work.

[@electronicsNmore]

Thanks Anthony! Be sure to rate thumbs up, share my channel with others, and look over my extensive video playlists for other great videos of interest to you.

[@Donderpad]

Can we have an article about cable resistance/airgap resistance, the latter mainly in America.?

[@johnsmith7676]

Indeed. This gentleman does commendable, thorough work and actually USES his brain... Something that, very sadly, has become very rare these days.

[@nicks9104]

Quick Tip: For continuity testing or even resistance you should always try an initial test by touching the two leads together first. Its not unheard of to have bad leads or connection to multi meter that may make you think something is wrong with the spark plug for example. Just good practice.

[@johnsmith7676]

Gee, ya think?

[@mr.smileyken6364]

Thanks for this video, I diagnosed a bad plug (which seemed totally fine), this got my generator running for $3 and made a lot of headaches go away.

[@electronicsNmore]

You're welcome Kenneth! Many people like you have benefited from the info in this video. Thanks for watching! Be sure to share the video link with friends.

[@michaelllewellyn7215]

i have had two strimmers inat the same time both with poor hot starting and both had a plug that goes open circuit tip to cap when hot let it cool and the connection come back very nice to find a fault like this

[@memylastname9972]

When I had the pleasure of working with a great racing mechanic Mario Deliotti I showed him that a plug I had out of my Alfa Romeo sparked perfectly well out on top of the engine. He laughed at me, called me something in Italian, and told me to put it the spark plug tester. I did and it sparked ok looking through the inspection window. Now I turned up the air pressure ( the tester connected to the shop air line) and at 80 psi plus it hardly sparked at all. Put a new plug in the tester and that lit up like a Christmas tree at any pressure. As an electronics engineer I have never understood why this should be but it taught me that a low voltage meter test at atmospheric pressure is worthless. Don’t waste your time just replace the plug.

[@electronicsNmore]

Never had the test fail. Your situation was highly uncommon.

[@that_swedejd9374]

At a guess you sound as if you are in your twenties and dont appear to work in the motor trade. I have a vehicle in my own garage that has just this problem. I call BS on your "uncommon" statement, if only because you haven't have enough real world exposure to have encountered it.

[@memylastname9972]

I am 67 and have worked on most vehicles in an auto electrical capacity, It was just something that I surprised me as an electronics engineer, and later help me when I was designing electronic ignition systems.

[@allansmith6140]

Yes that is correct, the higher the air pressure, the harder a spark has to work to punch through it. However you do not need anything as elaborate as a pressure chamber to test spark plugs "under pressure". Simply open the electrode gap to one quarter inch and it will simulate it for you. If you get a good spark like that its good to go.

[@memylastname9972]

That's a good tip but unfortunately these were Lodge 2LH plugs with the four point electrodes.

[@russg1801]

First off, this is a valuable test. Over the years I've seen too many outboard and power equipment owners automatically throw new plugs into a motor expecting that to be the miracle cure. Ninety percent of the time, it isn't. But, I never thought of testing the electrical resistance of the center electrode, which would be the only real reason for failure outside of wear or breakage of the insulator.

[@jeffball6108]

First time I've seen a video that recommends testing when hot. This is super important, especially if you have a problem with missing when warm, or even just an intermittent miss.

[@aussie2uGA]

This was very relevent for me, precisely illustrated the issue I was having, and here it's 2020. Thanks for keeping this on KZbin.

[@electronicsNmore]

You're very welcome! Always nice to have viewers from Down Under! Be sure to share my channel with many others. Thank you!

[@asiajanse1846]

This is seriously like the best video ever ! I was one of the "didn't know" people. Had no clue. I just switched spark plugs around and read codes. This is so much better. In my defense I'm Polish and I'm a girl so it's ok ;)

[@fredbach6039]

I can't speak for today but years ago Champion plugs came with a "booster gap" built into the internal connection from boot to tip. So the continuity check would read open circuit. The booster gap was there to make sure the available voltage was higher when the spark energy actually hit the tip. The idea was to be able to get a fast voltage rise at the tip despite some leakage to ground on the tip of the insulator.

[@js4512]

One small point to contend... I worked in auto part stores for over 15 years and have learned from reading the indexes that the reach of the ceramic on the combustion side of the plug is what controls the heat range. when the tip is recessed (protected from heat) it will be a cold plug. When the tip is projected into the combustion chamber, you will have more exposure to heat , and more ceramic material to hold the heat. Other than that your video is correct!

[@electronicsNmore]

+john smith Hi John. This issue has already been discussed in the video comment area, and I also placed annotations in the video to clarify things I said. :-) Thanks For Watching!

[@obfuscated3090]

Neat stuff. Every mechanic should have a heat gun (I've scored a few at yard sales so I can scatter them around the shop) and will try your method before and after heating up some spark plugs. A propane torch would also work and handheld thermometers are dirt cheap. To quick check plugs I shoved the end of a gas grill piezo igniter into an angled spark plug boot then ran some solid copper household ground wire around the shell so the ground contact on the igniter has a path to ground. (It normally grounds thru the gas grill body.) Wrap with electrical tape and you're done. Great for detailed arc observation without running an engine.

[@crpth1]

+Ob Fuscated - My heat gun is always moving around the workshop. Damn useful tool. :-) Neat trick with the piezo electric, I had an ignition simulator for testing but that's much better and small.

[@JasonSmith-qx3zh]

Let me make sure U hold heat on the plug till you read 300 degrees for a hot plug correct?

[@jimbohnenkamp5082]

I used the information on this video to check a spark plug on a snow blower that was not starting and had been used once or twice. The 2nd measurement on the existing plug, from tip to the body of the plug, was not showing the results that were demonstrated in the video. I sprayed the other end where the spark should be coming and got inconsistent readings. I spent $1.90 to replace the plug, and the snow blower started immediately. Thanks for the service.

[@electronicsNmore]

Glad the video helped Jim! Be sure to look over my extensive video playlists below for many other videos of interest to you, and most importantly take one minute to share a link to my channel with others. Thanks kzbin.infoplaylists

[@bobbailey8246]

I know you are dealing more with the electrical side of testing, but, don't forget to also look for signs of leaking gases around the insulator and signs of plasma staining on the insulator. Both are good indicators of ignition faults/wear and tear. I am hooked on your videos, great job.

[@168444]

Ttttttttttþttttttttttttttttttt

[@F.Krueger-cs4vk]

Engines usually miss at idle or under acceleration/under load. Can either be a faulty spark plug/high tension lead & or coil pack. Some engines dont have high tension leads, but a coil pack for each spark plug. When you accelerate/more power, throttle butterfly opens increasing air supply into motor. Fuel injectors stay open longer allowing more fuel into motor. Therefore the ignition coil increases voltage for stronger spark under more demanding internal engine conditions. You can also test each individual high tension lead using ohms/resistance scale on your multi meter for either open circuit or very high resistance reading. As a rule of thumb, high tension leads should have anywhere between 7000 to 12000 ohms "per foot lenght" of high tension lead, (7K to 12 K scale). You can also test your ignition coil pack in a rather crude way, like a bush mechanic without any tools. Start your engine, let the motor reach normal operating temperature. Remove nut or bolt that secures each coil pack to the engine. With the motor idling, gently lift the coil pack slightly off one spark plug at a time so you can hear the sound of the spark jumping from the coil pack to the spark plug. Dont lift the coil pack too high off the spark plug. You will hear a specific normal spark rhythum. Your listening for an an irregular/abnormal spark sounding rythum. That will indicate a faulty coil pack. This test is limited to engines you can access the coil packs individually whilst motor is operational. Unfortunately some engines, wont permit this limited test. Be sure to wear rubber gloves & tools that are insulated. Cheers from 🇦🇺

[@bennyrussell5551]

Actually we use to check the resistance at the end of the Seal line during the manufacturing process. We also did dielectric test to ensure the bisque had no pin holes. We made millions of every brand plug on the market. No one brand was different from the others. I know some guy just crapped his pants to hear this, but Champion, Atlas, Prestolite, Autolite, Shell, Sears and others were made exactly the same with the same materials.

[@ARKhan-ix8ef]

Genius Russell Ceramic clay is porse (having gap between Cristal) and carbon with fuet mixed oil gets penetrated during compressions created by piston , the cause of conversion to good conductor is the presence of same oil, so the Manufacturer should use cementing process of between grains gap . The easy , I obtained by soaking the center conical white clay with drops of Elfie (quick jointing liquid gum) that penetrates well in new, Un used spark plug. The life gets doubled with smooth performance. Try n see . my cont. [phone] ,

[@crpth1]

Bear Russell - I understand what you say perfectly. I always find quite funny the passionate discussions. French/American/ German/ cars is better than... something else. LOL :-) I worked for a very well known brand that among many others components, produced ignition coils. For anything American, French, German, English and so on, even Harley (motorbikes). Sometimes even part of the production line is the same... same workers under the same roof, etc. There are differences, but not where most people think. Surely not in the "brand". ;-) BTW the retail price is the most visible side of the story. LOL :-)

[@tresnotas1483]

Y7

[@lindah7534]

Well yeah, most products are marketed under various brand names even though they are manufactured by the exact same process. They all test the same, and operate the same. However, the issue occurs when the "Brand Name" is applied to the spark plug. The moment that the brand name "Champion" is imprinted on a sparkplug, its reliability is adversely affected.

[@jamesbullock7257]

Benny, hey I would like to chat a little if you find time. I knew what you mentioned above. Been indexing decades. [e-mail] I am an engineer re engineer of a few internal combustion systems and try chatting with guy's like you, thanks

[@robertlengemann4947]

I bought the same tester today at auto zone it's not $5 anymore but $8.99. Bit after seeing yours had to have it. Thanks for the tips.

[@electronicsNmore]

Glad you enjoyed the video Robert! Be sure to check out my automotive/mechanical video playlist, and product review video playlist. Thanks

[@caliwebman]

Straight up and to the point, clear speech, no bullshit. One thumbs up for you!

[@electronicsNmore]

caliwebman Thanks Cali. Please share my channel.

[@budirving7007]

caliwebman, How would shit from a bull get into a spark plug?

[@victoryfirst2878]

THis is hands down the best video on the subject Sir. Nicely done fella.

[@electronicsNmore]

Glad you think so!

[@breannachron392]

Think about this? If the ohm reading is 1.5 ohms or more, I believe the spark plug is going bad. This is especially true when it comes to ohming out electronic fuel injector solenoids for Cummins Diesel Electronic Engines. Thanks for the tip on spark plugs. I never thought of your testing method on spark plugs. Please keep those videos coming!

[@hoodwinkedbyanangelmichaelfazi]

As a Jet Mechanic I am glad you pointed out that the electrode could have cracks that and I might add that sometimes the cracks are not noticeable when the plug is cold but when the plug heats up the electrodes expand and causes a lack of Spark. It's funny watching this video I just went out and bought a tester this afternoon to test my Spark plugs in my new jet ski that I purchased that is not running and three mechanics have worked on and can't figure out why it wasn't running so I picked it up for 15,000 pesos in the Philippines with a trailer that's worth 25,000 pesos LOL because they couldn't get it running The motor itself according to the Spark plugs and lack of oil runs properly or did when it shut down so it hasto be a spark issue or electronics issue. Either way in a short period of time I will have ruled out any breaks in the electronic harness with the tester I purchased this afternoon and from there it can only be power pack which is as you note a sealed unit and must be replaced as a unit as a last resort. Absolutely ridiculous price of the electronic power pack in a jet ski GSX limited-edition SEA DO,,, $1000 plus shipping but it will be cheap if that corrects the problem considering I just purchased a jet ski worth 4000 American dollars for about $350 with a trailer that's worth more than what I paid for the unit and the trailer itself. Good upload and I will share it to Facebook.... not that any of the dweebs on my Facebook account would understand what you said LOL And I subbed your channel

[@hoodwinkedbyanangelmichaelfazi]

my friend I have been living in the Philippines for five months now and have in a beautiful Apartment with a view of an ocean which is about 50 yards from my apartment and deck which makes my view in Florida look like a Manhattan tenement LOL I have a white sand beach and Miles beautiful coral right behind the house and I just purchase a jet ski that I am working on in order to travel around the Philippines via the ocean traveling method... go to my channel then look at all the videos of over 100 I have made of the Philippines is a beautiful place... once you get past the fact that the people are basically not very well educated but are pretty much friendly to the American dollar and to the people and have them so I am enjoying the lifestyle here immensely. To see where I live you can Google Wish You Were Here in ALONA BEACH and thanks for stopping by

[@electronicsNmore]

Thanks for watching and subscribing! $1000 for the CDI/power pack.....what a bunch of criminals. I would try and remove all the potting material and swap out some components before I bought one. LOL . I would do a continuity test on every wire from point A to point B. My jet ski had one wire that corroded inside the insulation. Luckily I found it.

[@hoodwinkedbyanangelmichaelfazi]

electronicsNmore that is precisely why I bought the meter a.k.a. to test each and every individual wire in every part of the harness From A to B. All it takes is a small crack in the insulation in a little bit of salt water and it will corrode internally as you well know. Plus if I showed you the video I made of the harness you would see that the three so-called mechanics peeled off some insulation about 3/8 of an inch long and twisted the wires together without cleaning the wire itself prior to twisting it which means it may not have any continuity whatsoever because they twisted oxidized wires together not knowing anything about oxidation because they are not mechanics in the true sense of the word. I however went out and purchased a nice little wire brush some flux 40/60 solder which is still legal in the Philippines I'm the properly spliced them together laterally like this supposed to be. Went to 12 stores in the last week looking for some heat shrink... and no one even knows what it is here in the Philippines so I purchased some 1/8 inch diameter clear hose used fish tank filters and after the joints are soldered I will put some black high heat silicone over the wire and slipped the tubing over that which I'm sure will be sufficient to keep it from getting wet... The machine ran perfectly until it was left unattended for a few months and when the man went to start it again it just didn't start so probably the electronics is not the issue and probably more like one of the three fuses I found that were blown?? Do you think? LOL We shall see,,, it's the 1494 in. cubic centimeter engine and if you look at it in the video I make this week you will say it looks like it just came out of the factory however when you look at all the cannon plugs you can see that the high-quality brass male and females are completely oxidized. So I will take my little files and drill bits and polish them up in an out. Between that and a proper soldering job and testing the wires themselves I should have ignition when I'm done with that. There are some heat sensors on the top of each head and also in the exhaust loop and I'm not sure if they will shut the motor down what I will check those as well and the tubing that goes to the sensors. This is my first jet ski and it didn't come with a service manual so I will look online I'm sure it's there but only purchase this machine three days ago and this is not my livelihood is now my hobby which I devote 10 hours a day to anyway LOL If I have any questions I will be sure to bring them up on one of your pages after I do some research on your videos if it is not covered somewhere that I can find? If I don't I still believe it is something a lot simpler than the power pack and that is my last resort and you are right it's highway robbery. Okay my friend thank you for returning my comment and best wishes to you from one mechanic to another. Michael

[@nrmdm]

Where do you work at? Pratt & Whitney?

[@FourSeasonsNorth4x4]

HoodwinkedbyanAngel Michael Fazio I am so glad I came across this video and y’alls ‘troubles’ after acquiring these sea-doos. I myself have been given one and it too was a ‘it ran perfectly when I shut it off but will no longer start’ scenario. 👍👍 I say “perfect!” as it too does not have any spark. Seeing as I love electronic/electrical type work I welcome the challenge...and hey, for the price?(free) I am ahead of the game already if it actually does need a part or two. Any recommendations where I should look first on one of these beasts? I have done two stroke ski-doos of all types so that part is pretty familiar, just not their watercraft. You say the ‘power block’ can/may be an issue?..I’m guessing it’s to do with leaking water internally causing it’s many quirks. Let me leave y’all with one recommendation when cleaning up corroded wires....you will thank me for this later..trust me. Whenever/where ever you have corroded wires needing to be reconnected and you find ‘sanding’ them or ‘scraping’ them with a blade don’t quite do it, try dipping them in muriatic acid from the hardware store. This product is used for cleaning and etching concrete in pools etc. NOW BE BERY CAREFUL WITH THIS STUFF!!! IT IS HIGHLY CORROSIVE AND EXTREMELY TOXIC!! USE IT WHERE THERE IS EXCELLENT VENTILATION AND KEEP CLEAN CLEAR WATER NEARBY TO NEUTRALIZE IT WHEN DONE. It takes only 10-20 seconds of dunking this in the acid and it’s done..clean. Quickly rinse it off with the clean water and dry it off completely. Do give it a few passes with the emery cloth or sand paper to get that brilliant copper shine back which makes it the easiest to solder. I know the good heat shrink is the best but I see not always available. Check for a product called ‘liquid tape’. It’s black in colour and smells a lot like contact cement. (😮 💡 😮☝️👍...did the lightbulb just come on? 👍😉) ...I believe if there is no liquid tape available, you may be able to improvise with the contact cement...I’ll leave that up to y’all to figure out 💡😉🤞👍 Spread this liberally on and over the newly soldered connection right onto the wire’s insulation so no water/moisture can penetrate it. Cover that with electrical tape to help stop any possible abrasions that may occur. Thank you kindly for any tips you may have for me and I hope mine will come in handy for you. With any luck it won’t take me long to repair it as up here in northern Canada, our ‘Sea-doo season’ is already awfully short as it is..from October to June the ice makes for some powerfully rough and cold boating on a sea-doo anyway. 😆😆😁😄🤣 All the best from a fellow mech. and watercraft enthusiast. 👋👋👋

[@jeremyboyce1537]

Hi Mr.Electronics ,man you are from the future ,you are so knowlegable man I admire you ,just brilliant.

[@electronicsNmore]

:-) Be sure to share my channel with many others. Thanks!

[@raypearson4475]

came here after watching project farm, both of you are great and ill be sharing your videos too, well done videos!

[@10laws2liveby]

The best video on the subject I've seen. Been working on bikes all my life and learned something new. Thanks

[@electronicsNmore]

Thanks Tom! I have many videos on my channel that cover a wide range of subjects, so be sure to look over my video playlists below for other videos of interest to you, and most importantly share. You'll definitely enjoy my "Automotive" video playlist. kzbin.infoplaylists

[@grahamturner6119]

Better off to use an insulation tester as used for electrical installation work set at 1000volt scale /me Retired elecrician

[@garyscottfischer1846]

Wonderful video. I put brand new plugs in my Ford Taurus, and it was missing really bad. Broke out my Meter, and two of the plugs were bad straight out of the box...Thank you, you saved my sanity !!

[@electronicsNmore]

Gary Scott Fischer You're welcome. Be sure to check out my other videos, share, and rate Thumbs Up. Thank You!

[@Roger-eh7ez]

When I change plugs on a motor (about 3 times a week) I will test 1 of them on a pressurized spark plug tester. It will blow your mind what passes and what fails. You can't tell by looking at or ohming out a plug. Under load a spark would rather jump a 1" gap in free air than a 0.040" gap at the electrode under 100 psi. pressure. Also, a loose boot on a plug will allow the spark to run down the side of the porcelain to ground.

[@electronicsNmore]

That may be true, but the test does work and never failed me.

[@cravenmoorehead5636]

I just now found you channel. From reading comments on a project farm video. Holy cow do I have some watching to do. Glad to find you out there. Take care bud.

[@electronicsNmore]

Great to hear! Thanks for watching

[@olafzijnbuis]

This procedure only test for one failure mode. There are several other failure mode. Think of cracks in the insulator. Never remove a spark plug from a hot engine. As a rule: when you take a plug out, just screw in a new one. And do pay attention to the recommended installation procedure: - use of lubricants (many plugs do not require lubrication) - way of torquing (depends on seal used) - use a proper spark plug socket or risk cracking the insulator.

[@electronicsNmore]

Actually it tests (2) failure modes. An annotation was added which explains how to test the plug heated up to rule out any insulator cracks or heat related issues. Good ole toaster oven set for 300 deg F.

[@peterstencell804]

A merger would test insulation.

[@dh.mowersblowersservicesll4061]

In my opinion it's up to u or whoever is performing that task . Most mechanics should know how to test plugs . If u don't have time to test the plug then replace it . Or if don't have money to burn then test it. Do whatever works best for u .

[@stinkycheese804]

Most people don't know this because you don't need to do this. All you have to do is hold the threaded end against chassis ground to see if it sparks when cranking or running the engine. This will also indicate that power is getting TO the plug. If no spark you can repeat the test with a piece of bolt in the plug wire instead of the plug. You pointed to the wrong end when you indicated longer insulator means runs hotter. How far and thick it comes up at the spark end determines that. FYI, spark plugs practically never break apart in the middle, except possibly if you have trouble removing it and damage it doing so. Far more likely would be the tip has eroded away or is fouled too much, which might not be reflected at all in your direct contact meter ohm test. However this is all fairly silly. Once you've gone to the trouble of removing all the plugs (unless you have a specific cylinder misfire code), you might as well replace them. Spark plugs are not expensive in the grand scheme of vehicle repairs and far more often it's the hassle removing them in modern tight engine bays, not the expense that deters people from replacement, especially if it's a "V" engine instead of inline that has plug access at the top. As far as people claiming a plug is bad, that is very rare unless the plugs have so many miles on them that the owner already expected that it was time to replace them. I've been on multiple car forums for over a decade and am quite sure that spark plug paranoia is rare, except with specific engines known to, or evidence of excessive oil consumption which is noted by a drop in oil pan level.

[@electronicsNmore]

Your method is not a sure way to test the plug. I outlined all tests in this video which have been proven to rule out the spark plug as the cause of engine trouble. You must learn to read PINNED comments before posting comments. Lastly, do it your way if you don't like my method. I never force anyone to do anything on this channel.

[@chrisc6874]

Some might remove 4 ngk plugs on a motorcycle (which are easier to do depending on the setup) and pay $10 or more to replace them. Thats at least a 6pack ! Y not clean them and reinstall if they are good?

[@521CID]

Stinky Cheese. I just replaced 18 spark plugs on a lycomin R 680 radial. Most the plugs had a resistance of 9.68 m ohms, that's 968,000 ohms of resistance, 5,000 is the point of replacement. Huge difference, these plugs still fired at low pressure in the plug spark tester, but when the pressure is increased in the tester to simulate the high cylinder pressures, the plugs stop firing, those are bad plugs. You can test your plugs all you want like you have explained, but it means nothing if they spark. Because there are no cylinder pressures acting on them to reviel that there faulty. That's why an engine alot of time will idle fine, but when you accelerate and open the throttle valve, the pressure in the cylinders increase and the plugs start to miss fire, creating a loss of power. You need your multi meter set to ohms, 1000 to under 5000 ohms is good, and the SPCT spark plug tester to simulate cylinder pressures while sparking the plug. That's how you test plugs. That will reveal bad plugs.

[@cheriannsv]

I agree. Been working on vehicles for 35 years and what you're saying is true. Aircraft plugs are worth this test because they cost about $40 each, low end. Thanks for sharing.

[@PhattyMo]

The type/brand of plug can indeed matter. I (and some friends) have only ever had good luck with NGK "V-power" plugs in our older cars (mostly V-8's). They last longer/run better,in my (our) experience. Some newer engines can be picky about the brand of plug as well. (I've even had good success using the NGK's in place of platinum plugs,in some newer engines.)

[@electronicsNmore]

Hi, I never stated different types/brands of plugs did not matter, what I did say is the procedure outlined in this video works on all plugs. In my experience, using split fire / bosch platinum / NGK / autolite, I noticed no difference of performance with my personal water craft, cars, mowers, etc. I can probably switch out a plug that someone insists works better(without them knowing), and they would likely notice nothing. Thanks For Watching!

[@122martin122]

Sometime a plug can make a spark on the chassis and not in the cylinder head, its caused by the pressure, its a big factor in plug spark capability, and fooled plug can some time be recovered by burning the tips after cleaning it out with gas

[@521CID]

I see you talk about the resistor in this video as well. The resistor is to stop capacitance after firing of the spark plug. As the ignition system operates, the shielding in the plug wires builds up an electrical capacitance, ( just like a capacitor does). Once this capacitance is so strong, it'll jump the spark plug gap, this isn't good, so they build a resistor into the plug to bleed this stored electrical charge of slowly so that it does not jump the plug gap, and ware out the electrode tip prematurely. It can also lead to pre ignition. The electrically induced noise that you hear over your cars speakers is caused by the alternator frequency change when the capacitor goes bad in the alternator. The capacitor is an electric filter in the alternator, it performs the same job that the capacitor performs in an aircraft magneto p lead, it acts as a filter to filter out electrically induced radio noise. I'm not arguing, I'm just setting the info straight.

[@jamesbullock7257]

Great comment,

[@jamesbullock7257]

wanna chat let me know thanks

[@RussellBooth1977]

Well , I have fully rebuilt a Stihl hedge trimmer due to low compression & fitted a new carby due to having a leaking main nozzle check valve, the ignition coil was also replaced due to having no spark. The spark plug isn't NGK but their electrode resistance is 5 K ohms for their resistor type spark plugs,the plug I have measures 9 K ohms which I am told is too higher resistance which can cause hard starting & rough running , in my case I have a no start issue meaning that despite the spark plug having spark when removed from the spark plug hole there may not be enough voltage at the electrode to fire the air/fuel mixture in the engine. While the spark plug ran a Briggs & Stratton 4 stroke lawn mower I noticed the motor was harder to start & didn't run as smooth (surged) at medium to low speed (idle) ,actually it stalled at idle with that spark plug. NGK suggests a maximum of 5 K ohms from the spark plug terminal to the centre electrode,I am off to the auto parts store tomorrow to see if they can supply me with a suitable spark plug.

[@aodhmacraynall8932]

great video. good info and you are not talking about yourself like a lot of youtubers do.

[@electronicsNmore]

Glad you enjoyed the video! Be sure to check out my extensive video playlists as well as my recent bicycle generator video, rate thumbs up, and share my channel with others. Thanks

[@Silverline2572]

Excellent info! Had no idea all these years how to test plugs. Thank you👍

[@electronicsNmore]

Nothing is 100%, but it does work very well.

[@El-Buddah]

To locate a bad plug just remove the plug coils one at a time while the engine is running. If the engine idlization doesn't become rougher and stays the same that means that plug is not contributing to the performance. You can try cleaning the plug if it's dirty, regapping and blowing out the socket port in the engine for debri.

[@mattikaki]

If you have insulation tester, that’s better way to test the leak. It has high voltage of 500 or 1000 volts (most usual values, some have 5kV or 10kV) between the leads and measures the insulation resistance usually 500 or higher megaohms. Older models are available quite cheaply if they don’t have moren measuring algoritms. I found one in 30 euro. These are good if you measure HV cables too.

[@electronicsNmore]

Yes, a megger is great, but most people either don't have one or cannot afford one.

[@captainboggles]

yep the insulater is the bit at the electrode end of the plug, look under the electrodes, if the porcelain goes deep , it is a "hot" plug ie: there is a longer path hor the heat to escape to the metal body, if the central insulator is short and stubby, the heat escape path is short and effective, ie: plug runs 'cooler' ( a old plug) Cool plugs will oil up , hotter plugs will burn it off. ie: a champion n3 has a short insulator and a L7 has a long insulator

[@electronicsNmore]

Correct. My "Pinned" comment clarified all that.

[@doughunter3967]

good vid and info, I am old and have done many types of mechanics my whole life , I wasn't aware of this...thanks for taking the trouble to share friend...God bless...doug

[@electronicsNmore]

Nice name. :-) Thanks for watching! Be sure to check out my extensive video playlists below for many other videos of interest to you, and most importantly share my YT channel on social networking sites. kzbin.infoc/playlists

[@danfortin8429]

You offer good info for the info you have learned and it is kind of you to share this info with the public. I am searching for remedy for a small engine's ignition deficiencies that brought me to your video. However- please do let me point out that during this video you explain the "heat range" of spark plugs can be determined by the length of the ceramic insulator that remains outside of the combustion chamber during a plug's operation when in fact the exact opposite is the truth. It is the plug's business end that is within the combustion chamber that has a longer or shorter measure of exposed insulation or not that determines the " heat range" of that plug. A small bit of misinformation may have consequence of temporary or possibly immeasurable value. Such value compounds when the misinformed do indeed spread to others what they believed to be the facts. You have had over 1.6 MILLION views of this video, it is that fact which motivated me to point out one important fact of operation.

[@electronicsNmore]

The "Heat Range" issue was clarified in the video comment section a long time ago. Read my "Pinned" comment. Thank you!

[@joepaul9022]

good info . never heard that before . I was going to comment on removing plugs from a hot engine , but you covered that too . I have 4 plugs I saved I'm going to test .

[@electronicsNmore]

Thanks for watching!

[@StormieinFlorida]

Thanks! I have an older Ford truck and it's starting to get bad gas mileage, nothing else wrong, I keep up with it really well, clean air filters, the oil changes, anything it's needed gets done. She does have high mileage but it's never sucked gas like this in the 8 years I've had her.

[@electronicsNmore]

You're Welcome! Be sure to rate "Thumbs Up" and share. Also check out my other videos as well. Could be a loss of compression. Do a compression test. Any smoke in the exhaust? If not, could be dirty valves, or a fuel system problem. Spark plug wires/plugs can also contribute to a loss.

[@crpth1]

StormieinFlorida You might want to check the lambda sensor if your truck as one (or two). They tend to be forgotten and performance degrades with time.There's enough videos around to give you some insight on how to check it with a multimeter. Good luck ;-)

[@Airon79]

In the past I measured the resistance of the new plug compared to the resistance of the old plug and gave the plugs a tolerance of 20% . That is how electronic resistors are ; with silver standard being 10% and gold standard being 20% . The plugs I use are cheap and when my cars computer starts tripping codes for bad plugs they are usually around 20% .

[@electronicsNmore]

Thanks for watching Airon! Be sure to watch my "Auto & Mechanical" video playlist below, and most importantly share my channel with many others. kzbin.info/www/bejne/np_HaINthMSpe7M

[@dc112675]

Doug, thank you for your concise and informational video. A couple of questions...is it possible to test plug for spark while it is still in? Also, my specific application involves a non-working leaf blower, therfore i cannot test a "hot" plug; does that matter? My guess is that there are lots of people who are testing their plug because it can't "get" hot! Thanks again. dc

[@ScottTurnerformeindustrious]

Really good educational video thank you.

[@electronicsNmore]

Your welcome Scott! Be sure to share my channel with others, and check out my other videos as well. Thanks

[@briant3403]

i understand some plugs r cheap, but, we had a problem one year going thur champion plugs anywhere from two day to two an hour it was bad, anyway its nice to know how to be able to ck out if a plug is actually done, great video

[@electronicsNmore]

Thanks for watching! Be sure to rate thumbs up, check out my video playlists, share with others, and subscribe.

[@ben3318]

Much easier to remove the plug , ground it and check for spark while cranking engine, coil is easy to test and doing it this way can diagnose improper gap issues

[@xodrinker]

Thx for this video. What you are saying from 07:10 made me check and clean my spark plug thoroughly and now my scooter starts no problem! Great video. Thx again

[@reubenlopez3885]

Muy bien ilustrado,teniendo en cuenta que los manufactureros NO recomiendan quitar las bujías hasta que el motor se enfrie pero, entiendo que al hacer las .pruebas en frió al conectarlas otra vez para probarlas calientes, las podría dejar menos apretadas para que no vaya a ajustarse mucho da~ando así la rosca estando el motor caliente y así hacer ambas pruebas, Thank's.

[@scottcameron1476]

Allow the engine to cool down to a room/shop temperature. (most applications). Attempting to remove the spark plugs from a HOT engine may cause the spark plug threads to seize, causing damage to the cylinder head threads. ... Also contaminated threads may prevent the proper seating of the new spark plug.

[@somerandomguy3868]

great video very informative I've known about the lean rich hot cold what the pulg is telling you about the engine and fuel delivery thanks for taking the time to share your method of testing

[@electronicsNmore]

Be sure to check out my video playlists and share. Thanks!

[@mypropoganda]

Very good video..Easy to understand for even a novice like me and your explanations are very thorough.

[@electronicsNmore]

Thank You! Be sure to share, rate "Thumbs Up", and check out my other videos as well.

[@pigfigjig]

Hey good vid ..I once had a issue with a plug that was fine, sparked fine ,but when under compression would not function at all..it just about wrecked me.

[@electronicsNmore]

Luckily I never had that problem. It doesn't happen too often.

[@munsif55]

very good gentleman, I am driving 1000 cc suzuki cultus, four cyclinders, It is 2012 model, EFI. The engine started to miss on CNG and a repairman changed a sensor on carbeurator. but later I started to feel misfire or sometimes light blasts in left cylinder. I removed that plug and put it into right side cyclinder, but then I felt misfires in right side cylinder. I removed it and purchased a new one, however your tutorial was realy very informative, now I will check the removed plug, wether it was out of order, however it was newly installed. There was a loose connection which not only damaged the wire but also damaged the plug.

[@mohammednurgat7140]

JACK

[@TheNoah117]

Kishan Patel you're an asshat, kishen. I for one enjoyed JACK's story, so there.

[@gregwheaten8724]

Great video, concise and thorough and not boring as some of the educational vids on youtube are, these are important facts that anyone mechanically minded should know and in case they forget its good to come back and have this as a reference. Thanks! Big thumbs up :)

[@electronicsNmore]

Thank You Greg. Be sure to share my channel/videos with others, and rate Thumbs Up.

[@WV591]

TU good info..but if the plug is hot , doesn't that mean the engine was started/running so no point in checking it?.

[@electronicsNmore]

It was just an extra test to ensure the plug works fine when hot.

[@kr4mo]

According to NGK's web site, the heat range is determined by the length of the ceramic in the nose of the plug, not back at the wire connection.

[@electronicsNmore]

+kr4mo Hi there. I guess you had annotations turned off. Very bad when watching my videos. :-)

[@ranahamayun9919]

Very good job 👍👍👍👍 Nice video 👌👌👌👌 Very good teaching 👍👍👍👍

[@electronicsNmore]

Glad you liked my video! Be sure to look over my extensive video playlists below for many other videos of interest to you, use supplied Amazon links to support my channel when making purchases(No added cost to you), and share links to my videos with many others on social networking sites. Thank you, and stay safe! kzbin.infoplaylists

[@thomasgronek6469]

Many thanks for the presentation. More, and more frequently, resistor plugs are being used in small engines, Does that resistor further increase the spark's voltage across the terminals ?

[@edwinalexander1170]

Which one is defective now, as it confused when you get zero reading, but still you said it is ok

[@jimbos1567]

Very well done. Easy to listen to and follow. thank youl

[@electronicsNmore]

Glad you enjoyed it Jim! Be sure to rate thumbs up, subscribe, and look over my extensive video playlists below for many other videos of interest to you. Taking one minute to share a link to my channel with others on social networking sites would be greatly appreciated. Thank you kzbin.infoplaylists

[@miguelasantiago9543]

Thank You for those tips. Testing spark plugs before purchase them would save us time, work and money as well.

[@BrucesShop]

Very well done video. You explained it better than I did. (I did a short rant on replacing plugs)

[@electronicsNmore]

Thanks Bruce.

[@ourlegacy]

Love you clear concise no nonsense delivery and relevant annotations. Do you only do the cold and hot tests to rule out starting/performance problems that are happening within the maintenance schedule or to also extend the maintenance schedule of spark plugs. Would you then oppose the recommendation of replacing all your spark plugs at the same time? Thanks.

[@electronicsNmore]

ourlegacy The cold test is usually good enough(At least for me), but to be 100%, you should do the hot test. Replacing one faulty spark plug can make the engine run great again, but usually you would replace all the plugs at the same time. Thanks For Watching!

[@opinionsvary]

In my opinion: If you have a power gap plug or silicon resistor type your won't get any readings until a large amount of voltage goes through it. Not all plugs have the same type of resistor or have a straight through conductor.

[@supersevenn]

the difference in insulator length on a hotter or colder plug is at the other end of the spark plug.....not where the boot goes but where the electrode is. cheers

[@electronicsNmore]

supersevenn That is true, as I stated in the video with the use of an annotation, but usually in my experience, the nose length has a correlation to the insulator length. Shorter nose > Shorter insulator as well. I agree I could have stated it differently. Thanks For Watching

[@joe-hp4nk]

What do you think of spark plug blaster cleaner machines?

[@CameronDC-Grimes]

What is the range of KΩ you are supposed to get with automotive spark plugs with an internal resistor? You said roughly 6.3KΩ but I need to know the exact min and max! With 2 pin COP ignition coils it's: ▪︎ 1.0Ω or less for primary coil ▪︎ 6.0-8.0 KΩ for secondary coil I would appreciate it if you can tell me the resistance range for a standard copper E3.48 DiamondFire spark plug or any standard 98%Copper with 2%Nickel spark plugs and Platinum or Iridium if there is a difference

[@privateexposure7384]

Thanks for the great and most thorough information. GOOD TEACHER 🏁

[@electronicsNmore]

You're welcome! Be sure to watch and share my latest video. Thank you kzbin.info/www/bejne/oZqZnWuIeK6ld9U

[@brenthill5596]

great tutorial but the price of brake cleaner is the same price as a new plug where I live.

[@electronicsNmore]

Brent Hill You can use carburetor or brake cleaner "IF' you have it laying around, otherwise you will have to buy a new plug. Many people that work on engines have these cleaners. Thanks

[@Necrodoxious]

+Brent Hill that one can of brake clean will likely serve you multiple cleans. As mentioned, I think it is more of an option IF available. Not necessarily to go out of your way to buy brake clean vs a new plug.

[@amandaskinner4247]

+Necrodox ,

[@electronicsNmore]

***** Long Island. :-)

[@ThamMalaysia]

I do use carburettor cleaner for my spark plugs. However, it doesn't really whiten back the ceramic insulator around the electrode, which has been darkened by oil and carbon. How about those sand blasting devices ?

[@ralphv.2332]

I have heard different values with ohms readings (multimeter) for small engine spark plugs (mower, snow blower, etc.). Can you set it straight for me? Some say a good spark plug should read 500 to 5000 ohms. Others say 4000 to 8000 ohms. And still, others say 5000 to 15000 ohms. Which is it? Or, is there another standard of values to use?

[@hereIam1965]

good instruction . I use to clean rifle carbon buildup with vinigar .. don't know if it will work ..?

[@Wildcat5181]

Using a wire brush to clean the electrode and the anode creates a conductive coating that will short the current path. It is fool proof to use a spark plug sandblaster and they do not cost much at Harbor Freight if you have a decent output compressor but if you use a pancake compressor it might not work so well. Wire brushes do not like park plugs.

[@williampinson1125]

Great video, very informative. Thanks!

[@electronicsNmore]

Glad it was helpful William! Be sure to look over my extensive video playlists below for many other videos of interest to you, and share links to my videos with many others on social networking sites. Thanks kzbin.infoplaylists

[@luiscondori743]

Muy buena explicación ,

[@electronicsNmore]

Tengo un montón de excelentes videos en mi canal que cubren a muchos temas diferentes, así que revisa mis listas de reproducción extensa video para otros vídeos de interés, tasa de pulgares para arriba y compartir mi canal con otros. Gracias

[@petefrederick5362]

Very thorough and informative video. Thank-you. Cheers.

[@electronicsNmore]

Be sure to rate thumbs up, share my channel with others, and check out my extensive video playlists for other great videos of interest to you. Thanks Pete!

[@LEBANON707]

Thanks for this insightful video I am currently having an engine problem i.e. poor idling performance and I am glad to learn about this test. To make a long story short I have replaced the old spark plugs with a new Bosch brand but still experience loss of power. what could the probable cause be ?

[@electronicsNmore]

Hi, What you stated is exactly why I uploaded this video. You bought all new plugs that you did not need. Are you located in the USA? Many auto parts stores will allow you free use of their automotive computer code scanner. Using the code scanner will let you know if any problems are detected. If no code scanner is available, or the scanner shows no problems, then it could be many things. Clogged fuel injectors, dirt carb, bad timing, etc. Thanks For Watching! Be sure to share, and also check out my video playlists.

[@LEBANON707]

Thank you Sir Bad ignition timing seems a good guess ! It all started with sporadic misfiring at low RPM a few days ago. Upon speeding up, everything seemed OK. In the process of unscrewing the old spark plugs, the ceramic insulator shattered and a small bit fell into the engine cylinder (combustion chamber) I suppose this was an awkard mishandling on my own or it might well be that the spark plug was already worn out and cracked under extreme heat stress. We managed to partly retrieve it with a vacuum cleaner. When the engine was restarted, an ominous sound was heard which quickly disappeared after running the engine for 15 minutes at 1500 RPM. I suppose the engine managed to digest (desintegrate) and expell into the exhaust pipe whatever bits were left. Everything was back to normal however after travelling 15 kilometers a severe loss of power was observed. I will keep you updated as things unfold. The computer screening code you are talking about is called here a diagnostic suitcase. The car make is Ford Mondeo... Greetings from France

[@ericscaillet2232]

@@LEBANON707 ceramic powder will act as sand paper...scorred barrel, damaged valve seals, broken rings etc..

[@RussellBooth1977]

I have found out that the test was inconclusive with a spark plug in my Dads Honda GX35 line trimmer. While the centre electrode tested at 10K ohms & the outer to centre electrode tested at 130 K ohms indicating a short circuit,I burnt the carbon off with a propane torch,the resistance checked at infinity ohms so it tested o.k. The motor still ran like crap so I swapped it for the spark plug out of his Honda hedge trimmer then it ran like a beauty. The problem was it was apparently cutting out with 1/2 a tank of fuel in it so I checked & replaced the fuel filter with a new one,I cleaned the fuel tank out because it was dirty. I also pulled the carby apart & blew it out but it would idle for a minute or so then stall which would throw anyone off as being a fuel problem. The problem was the spark plug !!!!

[@electronicsNmore]

Never had it fail for me. I'd be willing to bet you cracked the electrode using a torch! Never use a torch. You clean the plug with a mini sandblaster or use carb/brake cleaner.

[@RussellBooth1977]

Spark plugs get red hot in an engine anyway & the resistance went up when the carbon was burned off. For the sake of a $2 spark plug I would be better off replacing it, the electrode itself may be faulty as the spark plug fails particularly once the engine warms up,maybe the electrode insulator is cracked ? I don't know !!!! I had trouble in 1994 with an old Honda motorbike which had worn rings where I'd take it to tech to use their sandblaster to clean the carbon off the spark plugs,it got to the point that a hotter spark plug became the band aid solution to the problem for a while at least,they also had a vacuum chamber at tech which simulated the spark plug condition when under load inside the engine meaning that the spark can be checked under vacuum, I don't have anything like that at home. My Dads Honda lawnmower has seen a fair bit of use in its 15 years of use since new,the spark plug is original in the lawnmower & I just clean & adjust it every 6 months for him when I do the service on it,it is getting a bit worn out now & eventually will need replacing.

[@vodonnell1]

Very informative video, thank you from Dublin, Ireland.

[@electronicsNmore]

Glad you enjoyed it Vinny! Be sure to look over my extensive video playlists below for many other videos of interest to you, use supplied Amazon links to support my channel when making purchases(No added cost to you), and share links to my videos with many others on social networking sites. Thanks! kzbin.infoplaylists

[@stevenherbert4315]

I have a snowmobile that eats plugs like smarties. Sometimes only get a couple minutes out of them. The plugs test good but will not spark. I've even tried them on different machines. The snowmobile is a 3 cyl 2 stroke. It's not the same plug that goes bad either. I'm very confused. This system fires all 3 plugs at the same time with 3 separate coils. Any Idea what would cause a new plug to blow but still test good?

[@das250250]

Do you expand on another video that point being able to tell what's wrong with an engine just from checking the tip of plug ?

[@electronicsNmore]

Too many others made videos about that. Thanks for watching!

[@Automationacademytv]

Thanks for sharing your knowledge very informative, it inspired me to focus more making electrical video

[@electronicsNmore]

You're welcome!

[@railrider1622]

Automation from another vid. 🤦‍♂️🙄

[@billr111]

Great information! Thanks for taking the time to do this fine video!

[@electronicsNmore]

You're welcome! Be sure to share my channel with others and rate thumbs up. Thanks.

[@PlayNRip]

Excellent and professional video. Thanks.

[@paulc7973]

Your multimeter will not produce a sufficiently high voltage to check the insulation of the plug

[@electronicsNmore]

paul c Never failed me. If you have a megger like me, use that.

[@mikem1014]

spark can jump 1 inch an your test never failed cause you probably only tested 2 .. by the time to remove plug test cold heat up test hot an realize this is a test but it is not conclusive or a positive diagnosis just but new plug for 2 dollars..

[@walterkersting1362]

paul c for that you need lightning.

[@mikeradu2010]

walter kersting - Hysterical response! Thanks for the chuckle. Love it.

[@couchrider6228]

paul c buying a new plug for $2.oo makes me laugh out loud.

[@ishtyaqali5164]

Excellent work buddy.

[@electronicsNmore]

Thanks! Please share.

[@lilman1796]

Thanks for the info on this ,very good ,great job ,keep up the great ☆☆☆☆☆ .

[@electronicsNmore]

Glad you enjoyed the video. Be sure to look over my extensive video playlists below for many other videos of interest to you, use supplied Amazon links to support my channel when making purchases(No added cost to you), and share links to my videos with many others on social networking sites. Thank you! kzbin.infoplaylists

[@axenz1]

Hi, Does it short when the plug get hot ? Thanks

[@electronicsNmore]

No. The plug heats up and expands, and if there is a cracked center electrode, that could pose a problem.

[@TheBigmachineman]

Great video with easy to understand info. Thanks for sharing.

[@electronicsNmore]

Glad you enjoyed it Steve! Be sure to look over my extensive video playlists for other great videos of interest to you, and most importantly share my channel with many others. Thank you

[@CSSIandAssociate]

I put plugs in my acuara I believe they were E3 the tip screws on and off. Do not know why. However if get plugs like this put lock tite on them. The tips got loose and the code was no help in tracking it down. I should have checked the plugs. But I did not. $100 later from the dealer felt like an idiot. I am sharing so you can be aware of it. Other than that I did not have any problem with the plugs. Thanks for sharing this video learned alot.

[@ROVITTv]

Good Explanation

[@electronicsNmore]

Thank you! Be sure to look over my extensive video playlists below for many other videos of interest to you, and share links to my videos with many others on social networking sites. kzbin.infoplaylists

[@philliphall5198]

I use a 1950 champion spark plug tester with air pressure It’s correct every time Then it cleans them to

[@Chuffin_ell]

Had to learn this the hard way. Wish I had seen this video first....

[@electronicsNmore]

Thanks for watching! Be sure to rate thumbs up, check out my extensive video playlists, and share my channel with others.

[@CZ350tuner]

From my experience working on bike engines:(1) Does it have NGK written on it??(2) Is it more than 3 months old??(3) Is the plug black??(4) Replace the plug with a better made brand (or just replace with another NGK plug if you enjoy frequent spark plug issues).

[@Zyggiespace]

+Andy Reid as a fellow powersports mechanic, I run NGK in all my stuff and dont have issues with them

[@CZ350tuner]

+Zyggiespace I own and work on a lot of 1970's 2 stroke bikes running more than 9:1 compression ratio and have found that NGK plugs don't like (A) high compression ratios and (B) 1970's 2 strokes that tend to "buzz" a bit when on long trips. The faults that is typical is that after 15 to 20 miles of open road high speed riding first the bike starts to cut out occasionally on one cylinder (or starts to judder on a single pot motor) when the throttle is opened up. Then the plug just stops sparking and the rider pulls over and suspects (wrongly) that something like a wire has come loose. After much fiddling and faffing about the fault has apparently cleared itself (the bad NGK plug has cooled down) and the engine starts and runs perfectly..... for the next 15 to 20 miles and the whole thing starts again. If I had a beer for everytime I've had this happen to me or friends over 35 years of riding motorcycles I'd be drunker than an alcoholic trapped in a brewery. I surmise, from testing the plugs before and after they've cooled down with a continuity tester, that the problem is that the metal rod though the porcelane between the electrode and pip on the top of the plug moves and looses electrical contact when the plug overheats. Once cold the plug returns to electrical continuity until overheated once more. Breaking open theprocelane on an NGK plug reveals that they are unconventional in the use of a copper rod rather than the more traditional steel or iron rod (as use in Lodge plugs and others) which might be the cause of the problem in that copper expands differently to steel and iron, causing it to break contact when the plug overheats. 2 stroke also run a lot hotter than 4 stroke motors, which doesn't help.

[@Zyggiespace]

I do know that the Arctic Cat 1100 turbo comes equipped with NGK MR8AI-9 plugs and those have held up to a substantial amount of boost pressure. That might have been an issue with them heating up and breaking in the past, and using a copper core (I have broken some on accident) but they dont use that anymore, Also, todays four stroke engines produce much more heat than two strokes.

[@CZ350tuner]

+Zyggiespace My local motorcycle repair shop owner confessed that the reason why NGK is the only brand they carry is because they have a higher turnover than when they stocked Nippon Denso, Champion, etc. and having worked in a motorcycle dealership in the recent past, the same was true with that place too. The repair shop owner said that when he sold somebody a plug they didn't need to replace it for more than a year or even two years. By comparison he can guarentee that a customer will need to replace an NGK plug per cylinder every 4 to 6 months on a everyday use commuter bike. He even spent 2 wasted hours trying to sort out an ignition problem on a customer's bike during a service only to find out that the brand new NGK plug he'd fitted from stores was dead as a Dodo. He reckons that QA has gone downhill over the years with NGK. Here in the UK NGK is the only brand that every motorcycle shop carries (good turnover!!) so try finding ND, Bosch, Brisk, Champion and as for Lodge, by sheer luck after searching the internet due to the high price. (I've had a set of Lodge plugs last through 3 bike engines over 8 years, but for what I paid for them, I'd expect no less).

[@Zyggiespace]

+Andy Reid back to your previous comment. I'm not sure what ratio you mix the gas/oil in these 1970s two stroke bikes. or if they run an injector pump. but I see a great increase in plug life, regardless of brand, if the oil is leaned out to a certain point. for example. 32:1 leaning it out to 40:1 or even 50:1. while gaining some slight performance

[@Manuel_Z_Kayaks]

WOW, you read my mind! I was just about to comment asking if I can just heat it up with a heat gun to test it warm. I have a 15 hp evinrude that will not fire, I was told it had good compression and spark but the seller was kind of a BUTT so, I'm going to get a spark tester to be sure. I put fuel in the carb, nope, put fuel in the spark plug hole, Nope!. If I pull it around 20 time it will POP!

[@crpth1]

phartattack If the plug test is positive, next would be to check coil. If that also returns positive go for the fuel. Carburetor on marine applications tend to clog mostly due to lack of regular use. Either case make sure you have new clean fuel. Clogged gicleurs is very common also.

[@SuperRamon77777]

How do we know what reading for spark plugs should be for year make and model of vehicle? & Also the readings for other electrical parts like ignition module etc?

[@electronicsNmore]

Hi Ramon. You can look up the spark plug number online for more detailed specs. Thanks for watching! Be sure to rate thumbs up and share my channel with others..

[@rolandos64]

What would oil or dirt… have to do w the function of the spark plug other than the thread? The thread would be ground. The core is sorrounded by the porcelain to allow current to flow through. Keeps it from arking. Only parts that hold any importance is the the end where the ignition wire clips on. The thread. Center electrode and the hangman piece

[@munsif55]

well , the test meter , whikle checking ohms of center electrode, might not tell you about any crack in ceramic, with which centeral electrode is coated. But, when such a plug is installed, the powerfull current might jump through crack, and engine might misfire, or malfunction due to increasing heat.

[@electronicsNmore]

Like I said many time before in this comment area, I've never had this method fail. You need to read my pinned comment too. :-)

[@M_Dub1]

Ik this might be a dumb question but say a goofball (moms bf) crewed off the tip by the insulator, would the spark plug still work? The reason he took it off cuz it didn't fit the cdi of my motorized bike