Lawn mower Ignition Coil - This is what FAILS in them! (by Craig Kirkman)

[@TheRepairSpecialist]

Hi guys I just wanted to Introduce to you my other Channel "Things to Know" - which i'm just getting started. It's a go-to channel for insightful worldly explanations, handy tips, and expert advice on everyday things and repairs of domestic items. Here is the link: kzbin.info/door/O8P9x5kUZ44Fb11vanLFsg

[@JohnThomas-hq4ye]

Great video. Lots of content. Well done mate !

[@markchaffee5306]

Mr. Kirkman, I am the fascinated owner of a John Deere Lawn Tractor approaching 40 yrs old. It looks its age, and years of keeping beautiful lawns. It was my father's, that he shipped to me when he went to live in the sands of Arizona. Each Spring, within the first couple mowings...I find myself flummoxed by something new that goes wrong as the mower goes through its aging process. This spring, it has been an electrical problem...and it seems to all now be pointing at the coil...after tests on ignition module, battery, and other wiring checks. I was looking for the part and stumbled on your site sharing videos of numerous things. I use to be a high school teacher, and then a college prof for 11 years. I know deeply the value of instructors who transport students from the shores of underlying curiosity...the gleaming shores of 'WOW'! I've rebuilt engines of all kinds...because it's something you do in the countryside...cheaper...and enabling some control over a world that wants to fall apart. I've rebuilt mowers, cars, tractors, combines...and each engine has parts that are like black boxes to me. They are 'parts' that I needed to understand their role...more than how they worked. Coils...have always been in the category of 'role'...having no clue what coil was 'doing'. I understood how starters work...but coils were almost literally...'black boxes'. And then this morning...stumpling on your video above...you made clear to me what was happening in the black box...and how. You do amazing illustration work...in a comprehensive and continuously visualizing manner that was so wonderful! Great teachers...are rare. You...are a great teacher! What an absolute delight is this video! I'm going to send it to a whole slew of friends just to experience the shore of 'WOW' that you make so accessible in your effort to illuminate. I'm editing a book currently that I've been working on for 4.5 years that is focused on illuminating the nature of human suffering and why we're so capable of killing each others kids so that a few of us might have 'more'. I'm focused on tearing apart the 'black box' of human failure to care effectively for one another...so that we might approach tomorrow differently. I'm tearing it all down to the 'wire', the 'insulation', the wear and tear and overheating and so on...to make our lives more visible that we might 'operate'...more effectively, efficiently...quieter. Knowing what I'm trying to map out to accomplish for my readers...what you accomplish in your videos is a beautiful job of educating a person at the level of the problems one is encountering. Such a wonderful job you do! Thanks for making me have a huge grin as I learned of what's in...one more black box! mark

[@adnacraigo6590]

You may have been in the small engine business for 25 years but you sound as if you would have been a great school teacher or laboratory technician. I worked on communications circuits for 31 years and your videos are spot on. I hope that more people begin watching your channel.

[@billcallahan9303]

I just subscribed Adna! Thanks for the reminder!

[@matthewtica4168]

I d HI L ca😂😂😢wear😂my dybyi😮❤ In pe🎉Sdzuhhbxgdh😅 😊of

[@michaellogue2254]

This is by far the best explanation of a coil on the internet.Thank you for taking the time to teach us.

[@TheRepairSpecialist]

You are very welcome, and thank you for your kind and encouraging feedback. Craig

[@johnsurges7981]

I am a science teacher and I cannot tell you how informative this video was. Excellent. This is real-life science in action. Thank you!

[@TheRepairSpecialist]

Wow, thank you! I really appreciate your feedback 👍👍👍

[@williamhinton5906]

I spent 30 years in the navy and commercial nuclear instrumentation field as an electronics technician, reactor operator and as an instructor. Your instruction is one of the best theory instruction I have had the pleasure to view. We done! Thank you.

[@jerrykeith9161]

“Good follow up video”…After 40 plus years with John Deere and 4 year Apprenticeship program, I still picked up some good information!!!

[@stefangr.9682]

I am a professional in Internal Combustion Engines and can say that this is a very professionally made and explained video so that even non-professionals watching it would become professionals. Keep up the good work.

[@AutismusPrime69]

Don't bullshit people

[@larryjones6049]

I’ve been working on small engines for 55 years. I’m still amazed that someone figured this out.

[@jpol3808]

I don't care what you work on as far as gas engines go..... Every single mechanic out there should watch this video! Many think a plug... Plug wire..... And coil are readily interchangable parts.... Wrong! This video is the most educational and well presented video I've ever seen about ignition systems with spark plugs and coils. Thank you for putting it together I know I did learned something and I'm not afraid to admit it...... Because it's something I can take with me to my grave and also use to increase my diagnostic abilities by double digits, when it comes down to ignition problems! That is a huge benefit over someone who doesn't watch this presentation. Great job. Thank you!

[@TheRepairSpecialist]

Wow. That’s some absolutely awesome feedback. Thank you so much. I really appreciate it. Craig

[@afzaalkhan.m]

Absolutely Brilliant. Concise and so clearly narrated for all sections of coil in a composed way. Very best tutorial on engine coils .

[@williamwaters4506]

The most detailed explanation of a coil that I ever experienced. It is amazing how infrequently these coils fail. I have a thirty year old lawn mower and I never replaced the coil.

[@carltrowbridge6748]

Craig...your video on "small engine ign coils" is the most comprehensive and precise information on this topic that i have found ANYWHERE on the internet! your explanations of ..how it works...and why its not?..along with the excellent illustrations/graphics and crystal clear audio has answered questions that i have been searching out for weeks...thank you so very much! CT Denver Colorado USA

[@blueplasma5589]

Heryaa is a very beneficial explanation! There is a condition called "aftermath heating" when you shut off an engine and the temperature rises a bit more than where it was when the engine is initially shut off. Some people can argue what part of the spark plug is negative and which is positive. Aggressively bending the HT wire excessively and repeatedly will break down the carbon powder wire core. A proper, strong spark is blue, a poor, insufficient spark is white and thin. Have (one) a nice day. LoL

[@davesipsy7587]

Superb! Your ability to break down complex information into easily comprehended concepts is world class. Thank you sir!

[@TheRepairSpecialist]

Wow. Thank you so much for your very motivating and inspiring comment. I really appreciate it. Craig 👍👍👍

[@mrc9464]

🎉- I feel like I just went through a class of coil 101! 👍🏻 your explanations (to a shade tree mechanic) are definitely easy to follow and using the illustrations along are HUGE for some of us visual learners out here. Huge thank you! I always looked at those huge chunks of coiled wiring with mystery- at least now I have some better understanding of how and what and why they are important and the absolute extreme care needed to have one stay working. Thanks for this video.

[@TheRepairSpecialist]

Awesome! Thank you!

[@scottfirman]

90% of the heat damaged coil is caused by an engine that is caked in dirt, grease, oil and grass or sawdust. Your key word was" fan cooled". I have gotten riding lawn mowers in with so much of a build up of dirt and grease, the engine was constantly shutting down. Push mowers and chain saws are victims of this issue. I always clean equipment I get in to repair before I even think about fixing it. Great video. This is basic stuff I learned MANY years ago.

[@teedee9903]

Absolutely Brilliant Sir. It is never too late to learn something. This video should be shared with anyone who works on engine. Bravo :)

[@terrymcdole6906]

Another simple explanation for a key component of the combustion cycle of a small engine. Great video.

[@terrystover7365]

Most excellent explanation I've ever seen on this subject. Top notch!

[@TheRepairSpecialist]

Thank you for your nice feedback. I really appreciate it. Craig

[@stuungar3390]

Brilliant tutorial as usual, thanks for the indept analysis. I never considered the resistance of spark plug type / gap / HT as a factor. Makes perfect sense now. Thanks 😊

[@billcallahan9303]

Here's something interesting for you. I fly Paramotors with 15hp at 9,000rpm tops, called a Top 80, made in Austria I think. Wouldn't start one day. Instead of my usual of tearing everything apart & finding nothing, I sat back & did some deep thinking. For the past week, we'd had cold, rain, fog, high humidity etc. Hmm? I smoke cigars, each one takes 25 minutes. Heat gun! I laid it near the coil & primary wire on low heat. Lit up my cigar, 25 minutes later, ohms checked perfectly at 10,250 ohms! Cranked on first pull! Sometimes it pays to just Stop & Think! Great show you got! Steve at Steve's Small Engine Repair too!..that wasn't his idea but I told him about it too..

[@TheRepairSpecialist]

That is awesome. Thank you for letting me know. You have my brain cranking on override now 😂. I’m so pleased you sheared that with me. I’m also pleased you follow Steve. His channel is brilliant and so is he. Thanks again. Craig 👍👍

[@billcallahan9303]

@@TheRepairSpecialist You're very welcome & thank you for the production work & great advice you offer to the public! Well done!

[@eddiesheeran5791]

Excellent explanation! I'm troubleshooting a cranky lawn-mower and I'm pretty sure the coil has failed. Testing coils is always super annoying because a lot of times, a bad coil will still make a spark when you're doing tests with the engine off! The mower's owner said the engine was running awesome, and then it turned off immediately. No sputtering, just died. It has enough compression to run, and the spark plug tip is wet with fuel. Hopefully a new spark plug & coil are the answers. This mower is 20 years old. It looks almost identical to the one in the beginning of this video.

[@TheRepairSpecialist]

Hey there! I'm thrilled that the explanation helped you out with troubleshooting the cranky lawnmower. Dealing with faulty coils can indeed be quite a headache, especially when they still manage to spark during tests while the engine is off. It's fantastic that you've gathered quite a bit of information about the symptoms-it really sounds like a failed coil might be the culprit in this case, especially with the sudden shutdown without any prior sputtering. Given that the engine has sufficient compression and the spark plug is wet with fuel, trying out a new spark plug and coil seems like a logical next step. It's impressive that this mower has lasted for 20 years! It's a testament to its durability. I have found that Coils can indeed show a good spark when tested and even read a good resistance when using an ohms meter, but when the coil is used, it fails after it gets hot. This is most probably because of the heat expansion effecting the internal connections. When cold all necessary connections are linked ok, the heat expands them apart. That's my opinion anyway. Looks like you might well need a new coil unfortunately. Sorry to bare bad news if this is the case. Thanks Craig

[@eddiesheeran5791]

@@TheRepairSpecialist I spent some more time on it & had great luck! There was a spot on the coil's kill-wire that was almost worn through and touching bare metal on the engine. I reinsulated that portion of the wire to protect it better. The steel plates in the coil were covered in oily grime between the flywheel and the coil, so I cleaned the entire coil & reinstalled it. The mower runs perfectly again, no joke. The coil isn't even bad after all these years. I didn't need any new parts to repair this problem. I love it when that happens!

[@netdoctor1]

Obviously a lot of time goes into assembling these instructional videos. A lot of hard work to create these easy-to-follow animations. I hope it's paying out for you. Thank you for sharing here.

[@akrm2944]

Wow, just wow. No question sir. And most surprisingly the video was posted ( the notification bell is On) at the time I'm looking for a solution for my bike jerks then stops after it gets heated and starts smoothly when it cools down 👌. Very informative. THANKS A LOT

[@bobbelsekwol]

I was given a 3 year old mower that had been stored outside since it was new. Low hours, like four or five, and could i get it to run properly. The carb was cleaned and cleaned , new plug and filter. It would for 1/2 hour or more then wouldn't start. Ended up swapping the coil with an old one and it runs great. I guess Britains rain killed it. Thanks for your vid.

[@Bob-cx4ze]

I would love to see this guy explain the physics behind a portable generator. His explanations are excellent.

[@cravenmoorehead5636]

Jeesh fella. You are gonna beat the coil subject to death ain't ya? After the last 3 or 4 of your videos I thought I had to have learned all there is to know about a cheap briggs coil. I guess I was wrong. Lol. Just messing with you. Nice work. Glad someone is sharing knowledge about this elusive part of the small engine.

[@mgomez5606]

I had one on a tecumseh that would not turn off after releasing handle. Removed bracket assy with kill switch twice to ohm check it and was good. I finally noticed the ground connection terminal on coil had corrosion. I cleaned it off to bare metal and put fielectric grease to keep it from corroding again. Mower turns off now. Was going crazy. Have to have good ground.

[@timgroleau1612]

Great video as usual. Don't for get to check the spark plug cap as I have seen many fail on motorcycles. Some have resistors in the cap as well as some plugs. The cap normally just unscrews from the plug wire. Then put a paper clip or like in the end of the plug wire and hold next to engine and check for spark.

[@fredmetcalf]

This is a phenomenally well done video....very informative and easy to follow....well presented.....greetings from La Grange, Texas

[@netdoctor1]

I had a push mower given to me a few years back. It was sitting in the weeds at this woman's house. When I asked about it, I was told that it had simply quit three years prior, and they simply left it where it died. She offered it to me, and I promised to feed back to her. She remarked that she had already replaced it, and I was welcome to it. I hauled it home and after I unloaded it from my SUV, I pulled the rope and it literally fired on the first pull. Three-year-old fuel. I cut a couple of strips before shutting it off to do some more investigation. Changed the oil, sharpened the blade, freshened the fuel and used it. It ran flawlessly for 6 weeks until the day it simply died. Long story shortened... the black hi-temp kill wire had developed a pinhole in the insulation and was intermittently shorting on the block where it was routed across to the kill switch. Replaced the wire and used it for the remainder of the summer.

[@JS-me5iv]

Excellent explanation video...coils are kind of an esoteric science in that they can pass all tests with a multimeter but still be defective...I think I'll just buy a quality new coil rather than go on a mystical quest to discover why my 4 stroke lawnmower generates +15K volts on start up, runs perfectly but upon inspecting the new spark plug, it's wet with unburned fuel * now, the start of the indiana Jones quest to find a quality aftermarket coil in a jungle of junk

[@theyeah132]

I would like to add another issue I have seen on small engines, this is technically not a problem with the coil/ignition module. Incorrect distance between the magnets on the fly wheel and the coil, this is common if someone has already tried to fix issues with the engine.

[@SouloftheTroll]

Bravo! Another VERY elucidating video!!

[@Syncop8rNZ]

Excellent! I'm hanging out for the coil testing video...

[@TheRepairSpecialist]

Thank you for your nice feedback. I will be doing an coils testing vid but with a difference. I have several vids to get through first through but I will have it sorted as soon as I can get to it. Thanks again. Craig

[@Syncop8rNZ]

@@TheRepairSpecialist The coil testing videos I have watched so far aren't clear enough and mostly cover lawnmowers. They talk about the tab but I have two tabs on my chainsaws' electronic ignition coils. They also can't agree on what a good reading is. 😕

[@bleo1017]

Been having issues with my powerwasher (similar engine to mower) and these videos were fantastic in helping to understand how things work. I have watched so many videos trying to get to my issue and this was the best. Now I just need to see the how to test my coil and sparkpulg with multimeter video to find out if that is my issue. (At this point I have replaced the carburetor, the air filter, the spark plug, changed the oil, and put in fresh gas but washer will start and run for a minute or so before shutting off. :(

[@TheRepairSpecialist]

Thank you for your kind feedback. I really appreciate it. Yes, I do have the multimeter testing of the coil scheduled in my list of video to do. I hope to get round to it very soon. I just have a few to complete first. Thanks Craig

[@brittweir8844]

That was a great video. very informative ,perfect illustrations easy to understand. Thank you very much, sir.

[@TheRepairSpecialist]

You are very welcome. Thanks you. Craig 👍👍👍

[@markmccoy8304]

Very nicely explained. Craig, maybe you have already done this but if not, delve even deeper into the Ignition Coil and research the "Iron Core". There is more going on with it than just being a lump of metal. I'm sure you're aware that the iron core is made up of many plates (laminations) and mechanically sandwiched together. I'm sure you'll find it quite interesting.

[@TheRepairSpecialist]

Thank you for your feedback I really appreciate it. Yes, in my opinion, the iron core research, would turn out quite fascinating and I will most likely look into that in the near future. Thank again. Craig 👍

[@dwaynecollins4974]

I've known for quite a while That heat causes coils to fail, But I never knew what caused the coil to overheat to begin with until now.😊

[@TheRepairSpecialist]

Thank you 👍👍

[@digicabtech]

Very well presented, and very detailed + the theory of the ignition coil failed.

[@TheRepairSpecialist]

Thank you. I really appreciate it. Craig 👍👍👍

[@michaelroach962]

Could a small break in the insulation still give you spark. But the spark is too weak to run the engine. Great video. Thanks

[@jimb4090]

One correction to an otherwise fine explanation. Water is a very poor conductor absent the mineral impurities that undistilled water contains. Additionally, one should look at the plug cable and connections, especially carbon track cables. These cables are nothing more than a string impregnated with carbon dust that carries the current to the plug. I've seen cases where the carbon dust is insufficient and has literally been shaken out of the crimp area of the plug cap's metal connector.

[@TheRepairSpecialist]

Hi, Thank you for your thoughtful corrections and valuable insights. You've provided an excellent clarification regarding water conductivity, emphasizing the importance of mineral impurities for water to conduct electricity effectively. It's essential to have accurate information to understand the principles involved in ignition systems. Additionally, your point about plug cables and carbon track cables is well-taken. The condition of the plug cable and its connections can indeed impact the ignition system's performance. It's a great reminder to inspect not only the major components like the ignition coil but also the smaller components that play a crucial role in the overall electrical connectivity. Your input adds depth to our understanding, and we appreciate your contribution to the discussion. If you have any more insights or questions, please feel free to share them. We're here to learn and help each other. Thanks again Craig

[@service1956]

I remember a long time ago my lawnmower would not start. It was getting gas so that was not the problem. I removed the spark plug but did not look bad. So I grounded the base of the plug against the engine with the high voltage wire attached. It was getting good visual blue spark. Reinstalled it and for the longest time, still would not start. I finally put a new one in and it started on the first pull! Sometimes plugs get fouled just enough, that they will not work under compression.

[@beannpersad8071]

Thank you for sharing your time and knowledge.

[@darrylsiemer5666]

You’ve given us a truly excellent explanation of the physics behind how small engine ignition systems work. However, someone with trying to troubleshoot problems with his lawn mower etc. would find it even better if 1) if there were some mention of what the gadget’s kill tab does & what its resistance to the magneto’s core frame should be , 2) some mention of what the resistance of the resistance between sparkplug lead and that frame should be, 3) a complete circuit diagram depicting what the ends of all three of the gadget’s coils are connected to, and 4) because it’s often difficult to tell if the engine’s flywheel is still properly keyed to its crankshaft, some mention of where its magnet ought to be with respect to the magneto’s frame at engine top-dead-center.

[@TheRepairSpecialist]

Thanks again. What you have mentioned will probably go into another video soon, Thanks. Craig

[@stephenbay9564]

This video was excellent! Thank you! May I ask? What is the difference between a single plug coil, and one made for twin engines? Do they have separate secondary's, or is it like a "waste-dump" set-up, where the plugs are effectively in series?

[@paulh3217]

Absolutely brilliant, so thorough with the explanation of how it works, what if causes etc👌 I also watched the previous video of how the coil works (definitely complex and need to re-watch it) but it gave me exactly what I was looking for. Truly appreciate your efforts in producing these videos. New subscriber 🥰

[@TheRepairSpecialist]

Thank you so much for your awesome feedback and for subscribing. I will keep bringing you more content now. Thank again. Craig 👍👍👍

[@boastyy]

Thanks for the video, very informative. Just removed a coil off a friends lawn mower and tested it with a multimeter on ohms and its dead no beep just shows outer limit. Will order another one but was curious why they fail and your video helps a lot, especially to check the spark plug gap, thank you.

[@simonsi787]

Thanks for this, I now understand why a coil went on a bike I built

[@victoryfirst2878]

This video is just what I was looking for to repair a coil from an engine that has not been made for years. I understand every part of this video. What I am still fuzzy on is the triggering part of the ignition coil schematics. Would you give more guidance in that particular area of the units Sir ?? Thank you for your time and help too. vf

[@brybrooks3648]

Appreciate this explanation well done.

[@CodeManDew94]

I'm only getting 48 volts from my ignition coil on my 5hp Tecumseh engine. I need 20k volts to get a spark on my sparkplug. Would it be possible my coil is partially damaged and still putting out 48 volts instead of 20k. If anyone knows anything about this please let me know:) The coil tests good on my multimeter but does not perform under load. If it is the coil that is my problem. I ordered a new coil, points, and condenser in the mail so we'll see what happens.

[@billbright1755]

Once the solenoid starting coil for my Kawasaki 82 KLT 250 went bad. Replacement was expensive so I disassembled it and found problem. Wire not much bigger than hair had broken. Unwound many yards to solder and insulate. Rewinding all again and refit in metal can housing. More than twenty years ago now and still working fine.😊 An electro magnetic device to contact heavy electron flow to energize starter motor. Lets a light touch start button to start engine ( 250 cc four stroke single, five speed gearbox).

[@TheRepairSpecialist]

👍

[@mp4338]

Heat destrois more electronic than electrical items. Darlington transistors, diodes, etc. are very sensitives and can be destroied. Less explication for insulation. Interesting that this small item can give more problems.

[@TheRepairSpecialist]

Yes you are absolutely correct. I do have another recent video explaining this a little more. If you get the time then please do take a look at it. It is here in the link. Thank you for your comment, I really appreciate it. Craig 👍: kzbin.info/www/bejne/ona8gGqeg7mYiJI

[@TheRepairSpecialist]

How an Ignition Coil Work. Full Video Here: kzbin.info/www/bejne/hH_PipWseb5ppqs

[@tadpoleman3879]

Really good explanation. On the secondary coil, doesn't one of the ends of that coil have to be terminated from the iron core? Or where does it be it start?

[@TheRepairSpecialist]

Thank you for your kind feedback. As for your question: In some ignition systems, a physical connection between the iron core and the ground terminal of the secondary coil can create a clear path to ground. This can help to safeguard the ignition system's proper operation and prevent electrical interference. Not all ignition systems, though, demand this connection. It is determined by the particular specifications and needs of the employed ignition system. I hope has helped Craig

[@DodgyBrothersEngineering]

Another extremely well explained and comprehensive video. While most of the things you mentioned seem quite obvious there are a couple that may not be as obvious. I half expected you to cover the magnet itself getting dirty or damaged.

[@boblynch7348]

A schematic of the ignition coil would be most helpful in order to troubleshoot the coil with an ohmeter.

[@jolsen6196]

I can think of only one additional case of coil failure thatI have personally experienced/ witnessed: tiny rodent teeth chewing through the insulation of the coil or HT wire...mice, chipmunks, etc. nesting in Lawn Mower shrouds is common in the States, and should also be included as a cause of failure...hope this helps...Cheers!

[@TheRepairSpecialist]

Yes, small animals do seem to like the rubber parts on carburetor primer bulbs as well. Absolutely.

[@MrUtubeobia]

You are showing a darlington pair of transistors in the circuit, but where are they located? Are they built inside the coil, and if I were to tear apart the coil, I could find them?

[@juanhernandez-qd9fx]

Excellent. Thank you

[@lostbutfound]

Good job, well done! And thanks!

[@williamdenny891]

Excellent video 👍

[@TheRepairSpecialist]

Thank you very much!

[@nathanrice1796]

I enjoyed watching this video.

[@JoeDirt-s2m]

I'm wondering if cold weather can affect the dielectric resin as the heat does. I have a stihl chain saw that was brand new. I used it a few times and stored it for a year in a shed. I drained the fuel and added fresh fuel oil and bar chain oil. I tried starting it with no luck . So check for spark , There wasn't any . So, a new spark plug still no spark . I replaced the ignition module and finally had a spark. It wasn't in direct sunlight, and it's rather cool in the shed. The only thing I can think of is extremely cold weather, which may have been the culprit in the damaged coil.

[@kenmccarthy8130]

I enjoy all your videos, especially on the electronics on a small engine. I have been experimenting, without too much luck, on using my Pico automotive oscilloscope to test the coil and analyze the spark waveforms. The waveforms do not seem to make sense compared to a 4-cycle ignition system. Have you had experience with this, or am I just wasting my time? Thanks

[@TheRepairSpecialist]

Thank you for your feedback, I really appreciate it. As for the waveforms. I’m not that familiar with them at the moment but now you’ve mentioned it. I might just look into it. Thanks again. Craig 👍👍👍

[@landmark4928]

Thank you you are a blessing to all you are A1 golden thanks all the time you put in to teach what your saying is awesome.

[@brittweir8844]

Great video sir thank you for the information I am currently restoring a vintage Stihl 009 chainsaw the coil wire looks a little rough. What do you think about replacing the coil with a Chinese aftermarket? I may just replace the wire if I can.

[@TheRepairSpecialist]

Thank you for your kind feedback. In answer to your question. I have used these aftermarket coils in the past. I haven’t had too much trouble with them in the short term but I am convinced that they don’t last quite as well. But, if you consider the price difference from the genuine coils, and there is a huge difference, then you can see why. I have found them to get me through a bit of a JAM in the short term if budgeting cost is an issue. So, I have found they work well, but I don’t like the thought of long term usage. This is my personal experience. Thanks again. Craig

[@0x00zero]

Please update to show the 'automatic up regulating' components. I would guess that higher lead/plug resistance would result in lower current and heat, and hence, less running. LOWER resistance is what I would expect to increase heat load by TOO MUCH current flowing. We can get to the bottom of this when you post the details of the 'self regulating' or 'up regulating' feature(s). thanks

[@yogibear6432]

Thanks again for a brilliant video.

[@SteveOwens-m4p]

I have a briggs and stratton engine which uses a toggle switch which closes a circuit from the kill wire tab on the coil pack and ground when closed (per design), when I measure resistance across the switch in either position it shows continuity. Disconnecting the kill wire from the coil pack and testing continuity between the kill wire tab and ground shows continuity. Seems like the coil is bad, yet when I disconnected the switch wires and tried starting the engine it worked and I am very confused about whether the coil is bad. I tested the switch out of the system and it's good, I replaced the switch with another switch and same thing. Thoughts?

[@akrm2944]

After I watched this video I decided it is an electric problem cause the same symptoms (stars easily and jerks and stops after few minutes when it gets heated) but the electrican tested it and said it is not an electric problem the spark plug works fine. My question is what's the difference between the coil problem and carburettor problem??

[@TheRepairSpecialist]

Well, they can give off similar symptoms sometimes but generally if the machine works until it gets hot (working temp approx) then this can be a sign of ignition coil issues. Unfortunately, testing the coil with a multi meter is not always the best indicator of a problem. This because the coil might go bad only when hot. The test is generally run on a cold coil. Carburetors usually, but there are exceptions, show issues from the get go. Please note again, though, that there are always exceptions to these types of diagnostic issues. I have a video coming out this, or early next, week explaining this and showing details withing the coil as to why it happens. Keep an eye on my next upload if you would like to see it. Thanks. Craig

[@HaroldPrittJr]

These little air cooled engines are bad about gathering dust , debris, and oils in the cooling fins . That’s hidden inside its best to run the gas completely out at the end of season . Now I change my oil after that . After draining I replace all plugs . Take the cover off . Use compressed air to blow all of the engine out around the out side were the fins are . If they look good . Then you can replace cover and put new oil in for next season . If there still dirty get some degreaser , oven cleaner , or pressure wash those fins out . Be careful not to damage any thing . Make sure your magnets are dry so they don’t rust . Towel dry the best you can . Use a hair dryer or heat gun to dry . Don’t get it real hot just dry the water up off the motor . So it doesn’t rust or corrode the metals that it’s made of . You’ll find keeping those fins clean makes the engine and the coil last longer and better performance with fuel efficiency! Great video thanks for all your great information I learned from you a bunch of different things and I watched your 1st video before watching this one . That sure was a great video I really learned a lot on how the coil works . I remember my dad would say the coil is breaking down when they got hot and wouldn’t start back up !

[@ringsidejudge4302]

Outstanding graphics and explanation . Just wondering do the magnets on flywheel ever fail ,and can a flywheel ever change position on shaft leaving the magnets out of line when the piston is at top centre . Just a DIYer looking for knowledge. Super channel which I have just found, many thanks .

[@rayfoster8198]

Could be that the flywheel key has been sheared, as in hitting something that causes the blade to suddenly stop.

[@mikkolempinen2717]

Too large spark gap can cause too high secondary coil voltage damaging coil wire enamel and finally shorting it to the turn next to it.

[@thesamur1813]

My lawnmower I was going to put up for sale bc I got a new one stopped starting after I washed it. I thought it might be water in the gas so I replaced that, and then ended up checking the carb, plug, and exhaust and everything seemed fine, plug was even sparking, but itll only fire muffled with even starting fluid, which makes me think something with the coil, before this, it started perfect without even priming, briggs and stratton 140cc

[@Ace-ig6vs]

Can you do a video on governors? Nobody explains things with as much detail as you.

[@TheRepairSpecialist]

Good idea! I will look into that.Thanks. Craig👍

[@EscuaDronVideo]

Very good, Tnx.

[@TheRepairSpecialist]

Thank you 👍

[@metalheadforager]

It started right up, thanks!

[@stuungar3390]

Great, can't wait for this!!

[@josephmiller1596]

So as the magnet is fixed to the crankshaft and not the cam shaft the plug would fire twice? Once just before TDC on compression and once again again just before the intake valve opens?

[@TheRepairSpecialist]

Yes absolutely. The spark plug does also fire at the end of the exhaust stroke. Importantly, there is no combustive air/fuel mix in the cylinder at this point, so no combustion of course, as it is prior to the induction stroke. That is my understanding of it anyway! I hope this helps Craig

[@bobstanden6579]

Love yer vido I have a mistory problem for you I have ride on mower That only done 100 hrs run time I bought a small contact tacho / hr meter To fit to it When I wound the contact wire from the unit around the HT lead The engine wont start (no spark) If I remove the contact wire it starts no problem ?? If I attach the contact wire to the HT lead After the engine is running, it works fine But if stop it again with the wire attached, The engine will not start no matter how much I wind it over It has electric start but just flattens the batt Way is the contact wire from the tacho robbing the spark ? I have tried two of these units now bouth do th same thing Is the contact wire robbing to much current from the HT lead The engine is a powermore ( chinies) with a Magnetron ignition coil Thanks for any help you my offer Bob

[@steveriggenbach90]

I have an echo pb251 leaf blower. It had different issues until it became very weak. I think the coil getting weak mimicked other issues. It acted as if it had vacuum block and bad seals. I thought that the weaker it got mixed with less fuel flow allowed it to run. Your thoughts please.

[@stav2421]

My mower starts first time, but if I stop - I have to leave it for about 30-60mins before it pull starts again. It sounds like it's not got a spark, but obviously does after a while. What's the best way to check if I'm getting a spark with just a multimeter or simple tools?

[@kenmccarthy8130]

Is the trigger coil pickup always visible? I only see the two legs of the iron core on most coils.

[@TheRepairSpecialist]

Some have these trigger coils visible and others don’t seem to have. I will make a vid on this soon 👍

[@Keith_the_knife_freak]

Thanks for sharing very interesting 👍👍

[@TheRepairSpecialist]

Glad you enjoyed it 👍👍

[@piercedasian9853]

I have a honda gx160 coil that might be a problematic one where it will work to start and engine and then out of nowhere, cut out and then restarting is near impossible. I took the coil Pitt and measured the primary and secondary resistance and the secondary resistance is nearly double what the factory spec calls for 5.9-7.1 kohms but my measurements are 15.9kohms. Could this higher than normal secondary resistance cause weak spark and what is the cause of secondary windings to have high resistance?

[@philliphall5198]

How about the new style Honda 4 terminal coil and how to test them and do they require voltage to them to fire the spark plug????

[@skanderchida9174]

Excellent video.

[@MarkAAshdown]

excellent video - thank you

[@davidhill8520]

Great content 👍

[@TheRepairSpecialist]

Thank you 🙌

[@garysenier2440]

I have a briggs 3.5hp coil that ohm tests good and checked the gap twice but no spark . I can only guess it is the transistors in there. It seems like there would be a way to test that aspect of an ignition unit but I never see anyone mention it.

[@TheRepairSpecialist]

It's frustrating when you've ruled out some common causes of a no-spark issue with your Briggs and Stratton 3.5hp engine. While the ignition coil and spark plug gap seem to be fine, you may indeed be onto something by considering the transistors in the ignition coil. However, diagnosing transistors specifically may require more specialized equipment and expertise. I have been where you are now with ignition coils, believe me, many-many times. I personally would just try a new coil on your engine if you have are satisfied that you have tested everything else, because transistors are not replaceable in a small ignition coil even if you found that they are at fault. There are so many small electronic intricacies within these coils that, in my opinion, you may probably never know exactly what is at fault, exactly. And as I mentioned, even if you did find the cause of the problem, those tiny parts are generally un-replaceable anyway. Sorry I couldn't help more. Craig

[@DodgyBrothersEngineering]

Did you wind up making the how to test video? That is the one I would find most interesting.

[@stuffoflardohfortheloveof]

Really interesting. Ta for posting 👍

[@TheRepairSpecialist]

Thank you for your nice feedback. Craig 👍

[@stuffoflardohfortheloveof]

@@TheRepairSpecialist Hi again…..watched your vid today as fed up with not being able to ‘prove’ that coil is either good or bad to enable eliminating it etc etc…..anyway, still can’t get my 4 in 1 to start and have spent a few hours trying, and seemingly failing, to find a replacement BUT (and here’s my question to you) do you know if it’s possible to fit a, for example, 52cc engine coil to a 33cc engine? In other words if it physically fits is there anything else stopping it from working. Just about to give up when I came across some eBay sellers with coils that look identical and suggesting that on the smaller engines they are interchangeable?? Any idea? Any help would be appreciated as I’m at a loss….thanks very much.

[@philliphall5198]

How does a solid state coil work ??? Like the Honda 4 terminal coils

[@davekri1662]

learned a bunch mate

[@TheRepairSpecialist]

Thank you for your feedback I really appreciate it. Craig 👍

[@billcallahan9303]

Excellence in electrical analysis! Even a blasted fool can understand this. I know I've opened myself to derogatory comments! :)

[@TheRepairSpecialist]

Thank you for your feedback. I really appreciate it. Craig 👍

[@freedomearthmoon1]

Thanks so much, very clear & to the point.

[@larryfine4498]

Mice are a major cause of overheating small engines. They nest on top of the cylinder head, blocking the fan cooling the cylinder and head. The coil as well as the. engine can be damaged.

[@TheRepairSpecialist]

👍