This Motorcycle Has Problems I Can't Figure Out (backfiring & erratic idle)

[@trxtech3010]

Motorcycle Repair Shop Owner here... As for the wierd irradic idle and ackfiring thing. What to look for that ALOT of people overlook is the Float Level being to LOW and it will cause a lot of the Symptoms you're dealing with. I have bikes all the time come to me and people will tell me (and they will think it's lean so they will up the pilot jet to a bigger one) then they will raise the idle then it will run but surgese and or revs on its own then stall and back fires through the carb etc... So what is happening is when the float level is to low... is the Pilot Jet is not submerged in the fuel and now fuel can be drawn up the pilot jet so the most common next move is people install a way bigger pilot jet now the things will rev up on its own etc so they try to mess with the idle Screw just enough that it's pulling fuel from the Main Jet since the Main jet sits low in the fuel bowl and now the pilot jet is acting like an air leak and pulling fumes in so it goes rich then lean people get confised over it. Once you get the Float jetting right make sure you have a stock pilot jet in it, then turn the Air Screw out little at a time you SHOULD hear the bike start to idle higher with the air screw then back the IDLE SCREW down then turn the Air Screw out again till the idle rises more THEN you will get a nice low idle with good throtle response.

[@joemurchie]

I was giddy with excitement for a moment when I thought we were going to get an update on the Shasta! Oh well, a man can dream.

[@jenniesgarage]

It will happen.

[@jamesg5059]

The off topic commentary is a big part of the charm of this channel

[@rcantin6182]

You guys are on a STREAK. Fascinating videos, amazing sound quality, general wisdom !

[@jenniesgarage]

Thank you, glad you are liking the videos!

[@zakksrage]

It’s been like 10 videos this year. Monumental achievement status

[@remyllebeau77]

Ahh the wonders of not editing.

[@starfox_wr-45e93]

@@remyllebeau77 I saw edits

[@remyllebeau77]

@@starfox_wr-45e93 Turning the camera off and on doesn't count.

[@whiskeythrottle333]

i had a xr650r with erratic idle...I wasnt there when i bought the bike, it came over time...I did find some bad seals in the carb (o-ring thing) but it didnt solve the problem. cleaned the carb 4 times. tried the spray test around the engine....no change. I gave up because nobody seem to know the cause. Wish I tried swapping the carburator to a replacement just to see if it was carburator issue. I think something isnt sealing properly, either carb related or crank seals maybe? I doubt that anything electrical can cause this behaivour for example bad stator. Good luck solving this issue, you are going to need it this time.

[@brantmcfarland517]

To ck for a vacuum leak spray carb cleaner on and around the intake boot and listen for a change in the eng. Do it with it running.

[@MotoMechzorz]

That's what I was thinking too. Could also be the o-ring on the air fuel mixture screw. When those don't seal and seat well they can cause the idle to hunt. Auto decomp would be low on my list of suspicions if I came across this scenario at the shop.

[@benburton8463]

Yes 💯 try these first. Air leaks are hard to find sometimes. Cracked boot? Or gaskets around the cylinder. Even top of carb. Check it all. Also no airfiller can make bike run crap! As it need back pressure.

[@aussiedigger1441]

He's tried spraying carb cleaner around intake with no diff in rpm.

[@BFG_2002]

I can’t believe you sold Elsa!! Those are some of the best videos you ever made I think. Every couple years I’ll go back and watch those videos and take a trip down memory lane.. next time will be sad!!

[@cory8398]

No one's going to mention the elephant...err...CBR in the room?!?

[@coconutcreampie3795]

I saw it :)

[@braydenstringer6444]

Lol I thought that's what he was gonna talk about but instead he got the ol IV pole out

[@pocillipora]

It’s red, hard to miss 😮

[@laz1go286]

At least he has 1 nice bike in the bunch..

[@bigdaddy741098]

I wouldn't even acknowledge the 1 or 2 negative comments, they deserve to be ignored. I enjoy your content, sometimes I learn something, sometimes you make me laugh, your videos are always enjoyable... and I think radio waves would perceive you the same way, as positive and solid content. 😅👍

[@MikeSmith-rx4uu]

I own a motorcycle repair shop in Florida. I deal with older bikes ALL the time. My assessment is carburetor related. Have you been inside it yet to know what the jetting is? There is obviously an aftermarket exhaust on it and some could have changed the pilot jet. It shouldn't have been changed. Put the stock size back in. I'm guessing its a #35 or #38. Either way put a stock one in it. Second is the fuel mixture screw. Remove it from the carburetor inspect it. It should be a spring, metal washer, then a rubber o-ring in that order. Look at the tip. It should be tapered to a sharp point. Not bent or broken. When reinstalled if all that is good ,a general setting is 1 1/2 turns out, to start. Next start the bike and let it warm up to operating temp. Then drop the idle to a slow as you can get it to run without dieing. Turn the mixture screw out counterclockwise and listen for the idle to increase. Keep turning the screw until you aren't gaining any more RPM's. Then set your idle screw on the side of the carburetor to 900-100 RPM.

[@kartracer5g229]

@MikeSmith-rx4uu why wouldn't you want to jet for the aftermarket exhaust when its recommended by basically every manufacturer I've ever heard of or had personally .. I've hmf, fmf, white bro's and countless others and all my machines had to be jetted accordingly to get them to run correctly 🤔

[@patrickdk77]

I have always had to adjust the pilot jet, but that involves exhaust and intake modifications. He did change the whole carb with a different one, we dont know what the jets where in the old or new though I dont remember.

[@Ajaxaxxess]

intake leak causes same issues.

[@jameshisself7375]

@@kartracer5g229 It will still run right if not jetted for the pipe. This is part of the troubleshooting process, once the issue is solved jetting for the pipe is recommended.

[@scottjankowski8031]

Air intake boot split or bad crank seal drawing air

[@lucasbord1983]

Dude, you cannot listen to the negative comments. Read the comments, read the positive comments do more of what the positive comments say. If the comment says we really liked that you did x, then do more x if some a hole says you shouldn't do this, ignore it completely. You're kicking, butt, keep up the great work man. I'm telling you, you are doing the bad chad style.And he has millions of followers, millions of views keep up the great work

[@rewa273]

By the way it fluctuates in rpm i would say you have an air leak in the intake boot making it lean. It would also explain those backfires. The quick test is to spray the boot and check if it changes rpm. If it doesnt, i would go to fuel starvation with the float level. If none of the above, as everyone says a leakdown test will give more information on the engine health. On the other side what you tslked about with the radio waves remind me of the movie "lucy" with scarlett johansenn were they show what would a human being with more brain capacity would see the modern world, interesting concept.

[@rewa273]

BTW nice cbr mate

[@HeyItsJonSchwartz]

On the one hand, I appreciate your perspective on things even if you don't understand them. On the other hand, your advice from a few nights ago was to not trust people trying to speak to you about things they don't understand... so....

[@jeffferguson899]

i cant believe you sold the ct90/125 that was my favorite video series

[@RY4NP]

Check for vacuum leaks with the spray trick, if that doesn't work i reckon remove the carb again, remove the jets and make sure they're stock size and they're clean and the air/fuel screw is set to oem specs. And see what happens.

[@TomsTinkeringandAdventures]

Check and adjust if necessary the valve clearance, install the air box boot and air filter.

[@Sixty7racing.]

Check an adjust the float height, a lot of people over look float height when adjusting carburetors ,if that is off it will cause the issue you are having 👍🏻

[@adamgarner2059]

I love your content! Especially how original and fun y’all are. I had a similar issue on a 1993 model I owned last year. What a headache it was! Adjusting the idle helped it not die off the line. Had a tick, especially under power and in hot weather that flowed with the RPM. One day, I could only start it by pulling it and it ran HOT. Made the pipe glow. I found out that the wires at the stator were shorted out and caused all of those issues. Purchased a 96 model stator, swapped a wire over, and it ran GREAT. Wish I never sold it. Hope this helps on your diagnostics

I like the actual hospital IV pole stand, it cracked me up that you're using the real thing, but come to find out, it's actually a really simple badass idea, wheels and everything, very versatile. 😁👍

[@ivanduka2906]

Aww that is such a cool bike. I'm sure the new owners will enjoy it very much.

[@muffinthepug2358]

I think it's pulling a little bit of air somewhere. So inlet manifold close inspection - then maybe if no joy - do a cylinder leak down test in case its base or cylinder head gasket leak, third thing could be a valve leaking. I'm right with you in frustration mode. Don't give up Jake, your a smart chap.

[@krisley5178]

That yellow Trail 90 was a beauty. I think you've got that Suzuki running better. Might wanna spray around the base of the carb with some carb cleaner to see if maybe you do have a vacuum leak somewhere.

[@edwardchamberlain7858]

Nothing is truly free in this world. But if you change your prospective, that carb came with a lot of free frustration. And with that a learning experience.

[@Deng1neer]

I would take a deep dive into the electrical components something could’ve been cooked during the fire. Great vids!

[@DirtbikeDoode]

Jake. I’ve been watching you for a very long time I even messaged you about my old Kdx80 way way back when… since before the ol blue tarp husky video you tear me apart Anyway everybody is saying air/vacuum leak which I think is correct but much more simple than we’re all making it. That’s a tm33 pumper carb and they have air jets in the airbox side of the carburetor. You don’t have a boot on there connecting the box to the carb which I believe to be necessary for that carb to work properly. You know what a velocity stack is and I think the air boot would act as a velocity stack accelerating the air coming into the carb making it run more proper Second thing I could offer is adjust your valve lash!!

[@exCR-it3ex]

A good test to perform is a leak down test. Pressurizing the cylinder to diagnose if rings are good, valves are seated well if there is a leak in any of the gaskets or seals. Set the piston at tdc lock it in place and fill the cylinder with air and see if you're inside the percentage of acceptable leakage

[@MainelyMoto207]

You can and should talk about whatever you want, it's your channel. Nobody is forcing us to watch it

[@GratefulEd907]

The ct90 videos walked me through my ct110 project. Cool little bikes

[@garageliving3658]

If we could see in infrared, that'd be a whole new world. Or be able to see sounds, or all light frequencies. Same with time as far as how fast or slow time goes by or atleast percieved. Its all a matter of perspective and awareness abilities.

[@edwinarmstrong9175]

There are frequencies that do go through metal. Starting in the microwave spectrum. You were not completely right, but I would hope others would look passed that since your videos are informative to a point, but most of all you are great infotainment!

[@imjacobyy]

I’d be looking at the slide on the carb, maybe the slide needle is out of adjustment. i don’t remember if you’ve looked at that already it’s been a while. Vaccum leak was a good idea. I was thinking fuel flow. Good luck 👍🏽

[@brandonkostrzewa8470]

i just sold a 83 gs650 that i got running after sitting for years, first start it ran great next day it was idling out of control going straight to redline. cleaned the carbs valve shims was good for one start then it started revving out of control again what a piece

[@rogerthat.9105]

Let me know how you make out with this problem…I have a craftsman yt3000 that’s doing the same thing

[@PremixandPedals]

I love your videos...love Camera Girl's insights...lol! I love to hear your views, it is always good ro look at things from different perspectives!!!

[@rhiantaylor3446]

When you talked about an early project, I initially wondered if that might be the cheap faulty generator you fixed by replacing piston rings from a non-original source. Great little series you should try to repeat - broadens your audience.

[@RY4NP]

A fluctuating idle is a lean condition. I've had this once before where the fuel flow from the tank was partially blocked from debris in the petcock and fuel hose. However, you've bypassed that all together with your fuel tank on a stand.. which means it's carby related or intake manifold leak.

[@hoosiertrailrider]

I would run a leak down test. Also check timing mark on the stator plate for the kick back problem. If the mark is lined up correctly you shouldn't get a kick back. If the timing chain is worn you can advance the stator 1mm to eliminate the kick back.

[@Cochis3]

I throughly enjoy your thoughts on things an stuff, thank you for the awesome videos guys 😊

[@Ohhighbud]

Check and adjust the valves. Then diagnose anything else as required. Had similar issues with an '03 klx 300.

[@gregm6913]

It soinds kind of like it could be sucking air somewhere. Get a can of starting fluid and while its running start spraying joints, little shots of starting fluid (where the air intake meets the carb, where the carb meets the head spark plug hole anywhere it coild possibly suck air into the combustion chamber) and listen for a change in RPM. Also worth checking the accelerator pump on the carb if it has one for the cut out when revving from idle. I had a YFZ 450 that did something very similar and i spent weeks testing it, it ended up being a little sensor in the throttle (the box on the handlebars) was a little grimey i cleaned it up and it was fine after that.

[@michaelwheeler7999]

Loving the videos man , never stop posting.

[@justinwhite3439]

kudos on ths cbr shaped easter egg idea

[@peterhallbus1114]

I've had the same symptom a few times, once it was the pin holding the rockers that had gotten starved of oil so the valves did not open the same amount all the time and that time I also had en extra noise from the rocker cover. Once it was the needle valve that was not closing perfectly (clean carburator and the rubber tip felt fine) but replaceing the needle valve fixed the issue. Once it was a tiny vacum leak between the carburator and cylinder.

[@jenniesgarage]

Thanks for the ideas. I thought your last one I thought might be issue on the DR but I sprayed carb cleaner all over the manifold and couldn't tell a difference.

[@peterhallbus1114]

@jenniesgarage sorry to hear that, could have been an easy fix. Only other issues I've had have been electrical in the form of a bad cdi and ignition coil but that also gave issues at rews in my case. Anyhow nice that you are getting more videos out, they are an inspiration.

[@Iseekoutthetruth]

I Like The IV Gas Tank. String Theroy.

[@jenniesgarage]

Thanks! I've already used it twice and I've only had it out 1 day.

[@martygiron6687]

Certain types of radio waves will go thru some metals. The only for sure way to stop radio waves from entering or escaping, is to use copper or gold cladding.

[@caseyc1742]

You e got an awesome channel with great candor and engaging teaching. I just got into bikes and bought a 98 dr350 off-road model that I’ve spent two months getting ready for the trails and had similar issues to you with rough idle and bad exhaust pop on decel. I missed of your bike has the pumper carb or not? Most of my issue was carb and fuel related. I did adjust the valves to spec but most of my problem was in the carb. I also replaced the header gasket and that seemed to resolve the popping and could also be affecting the idle mixture. You’re far above my mechanical level but thought I’d offer what worked for me.

[@haydenw6585]

I would think an air leak would cause that idle fluctuation spray the intake area with carb clean so determine where it might be Good video ☝️

[@goofesgts]

hey jennies garage you guys really need a motorcycle/quad table jack\lift , poor man squatting all the time or on his knees to fix the bikes. its a game changer and back saver if u get a table lift\jack.

[@goofesgts]

love youre videos . keep them coming!!

[@edwardchamberlain7858]

And a tool cart, with blow molded tool trays, and a place to put every socket, and every wrench. But you gotta put em back in the tray every single time you put it down. Hey this has po-ten-shall.

[@Mrzizzy69]

I was thinking vacuum leak at the moment you said it.

[@Tall_blue_grass]

Thank you

[@rmccagle]

Correct can timing verified. Confirm float level. Bring to tdc. Clamp air coupling (make one) on intake boot. Charge with air (10psi). Use soapy water to find leak. My guess it’s a leaking crank seal behind the magneto or a cracked intake boot.

[@aussiedigger1441]

I love you guys! Giday from Australia 🇦🇺

[@rm25088]

Vacuum leak may be a good place to check like you said. Does it have an accelerator pump? That may be why it dies when throttle is applied? Carb could just be worn out. Cracks in intake boots. I would be aiming for a vacuum leak somewhere for sure.

[@a.m.v.6938]

Take some startling fluid spray and while bike is running spray a little around different parts of engine, when engine idles up you found your vacuum leak.

[@turboconquesteob]

The iv setup is cool I’m sure it will be handy in a garage like Jennie’s. Even though you’re not a carburetor channel

[@MichaelVaughn-p9f]

Damn good job on that bike

[@jenniesgarage]

Thanks! It has me stumped now but hopefully I can get it sorted out.

[@SuperHurdman]

like GOD! Some know he is here some don't some don't care!

[@kartracer5g229]

The way its kickin back like that even with the compression release id be willing to bet there is an ignition timing issue

[@patarmstrong3582]

Love how you doubled down and sent the naysayers packing. They need more shrooms on their pizza.

[@BiscuitTinOrchestra]

these DR are notoriously hard to cold start without backfires, check the valves are fully sealing, and valve clearances are correct. also check carb rubbers are not perished

[@nicolauscory2065]

I agree with others, put it back to stock as much as possible. Jetting and air filter.

[@bertamusprime618]

Another great video!

[@louisgohler1303]

I‘d still suggest you to check the valve clearances. Can have a lot of outcomes with even slightly too tight clearances. Correct me if you did check them ;)

[@Frrlas]

My kx450F -06 did simular to this and wanderd from 1800rpm to 2200 and it was a bit lazy taking of from idle and did die some time. it was worse when it was cold to about 20 minutes then it ran "fine". I finally took out the carb knowing everything else was just fine and "new" I raised the needle 1 level, and after that it was rock solid 2000rpm idle from the start and about 1800 warmed up, and quick as he\\ on the throttle it almost threw me of the first time. only thing I had to renew my skills starting it up cold.

[@spidermurphy5967]

Loving the content. keep it up and thanks 🏍🏍🏍🏍🏍🏍🏍🏍🏍🏍🏍🏍🏍

[@32road]

Love the videos…like a brain teaser ever time😁.

[@SuicidalRiot]

I had the same dirtbike. It was pretty bullet proof. Ran the piss outta it never did start smoking. I always thought the swingarm on em was crazy design.

[@timothyhatcher8673]

Valve clearance and the air leak on the part where it connects to the cylinder head

[@daviddc7906]

Maybe check the needle on the carburetor slide? It could’ve come loose, and somehow, it fluctuates inside the carburetor slide, giving it gas or taking away gas. It's kind of a long shot, but maybe the needle could be bent, too. This has stumped me; I've never heard of this happening before. I've seen engine idles fluctuate, but nothing like this. Hope you get it figured out.

[@plumpii7177]

7:41 in my head I could hear tim the toolman taylor doing the ruff ruff ruff.....as you wheeled that out Man's iv, 98 octane

[@3wandjina]

Yeah, vaccuum leak, maybe around the intake manifold. That would explain off throttle backfiring you mentioned as well.

[@Nunya_Beezwax]

Since it has no air filter, and aftermarket exhaust, I'd say the pilot jet is too lean... BTW, Jennie's garage looks tight..

[@retrozmachine1189]

Nurse! 100cc of premium STAT!

[@NikMartin-I-am]

Can't say that idle hunting issue would bother me that much.

[@laz1go286]

You should ride around with IV bottle like the Bearded Mechanic does😂 It's hilarious..

[@metaldog7128]

Some of us will understand what you mean Jake but others won’t because they aren’t really listening to what you’re saying…those people don’t matter because they already know everything because someone taught them something and that’s what they will stick with… i think you me and others like us will also look at other possibilities has to why something is the way it is?

[@edwardchamberlain7858]

WOW, very well said, and so true. Other possibilities, exactly.

[@kyferez1]

That sounds like an air leak. I've been thinking that all along but usually they speed up not stumble and die, but with the cam fixed it's sounding much more like a small air leak. Once it warms up a little and begins acting up Spray carb cleaner or break clean around the head and carb boot and see if the engine speed changes. Might be the carb boot or the head causing the leak, but it definitely gets worse as it warms and that is typical of air leaks.

[@lajosdravecz9887]

Hi you must install the aire box and airefilter and a carbutator is fixt and a machine runing is good as vell

[@moverplus2853]

I love the drs

[@kevinmccarthy1330]

Try checking for vacuum leaks with some carb cleaner or brake clean. If theres a leak rpms should go up. 🤷‍♂️

[@jenniesgarage]

Good idea. I tried spraying carb cleaner around the manifold but couldn't tell if there was a difference. Tough to tell because the idle randomly fluctuates anyway.

[@JonnieComp]

Do you have the air cleaner box and filter on..sometimes you merd that internal resistance from it,..or re adjust the mixture screw while giving it throttle...

[@Douknowgregg]

That bike has a tm33 or 31 pumper carb on it. Make sure the pumper rod isn't stuck open it will flood the motor..the plastic arm should be on the right side of the carb with a rod extending down into the float. I will link a video of my TM31 carb install on my DR250

[@Douknowgregg]

kzbin.info/www/bejne/epezaZlsf951fa8si=QcYgNZqUuHW-H8C7

[@VashStarwind]

Maybe the crank timing is off. You said that the mark in the inspection hole was when the engine was nearly at top dead center but that doesnt make sense, those marks should all be lined up at top dead center. Maybe that is your timing problem. Should check the shop manual it will tell you. Also, you can check for vacuum leaks by spraying carb cleaner around vacuum hoses and and vacuum areas, and listen for an obvious idle change. The carb cleaner gets sucked into the vacuum system and changes the idle if there is a leak. Helps to narrow down and find leaks. (edit: saw you already tried that) That click does sound like the decompression lobe engaging/disengaging

[@VashStarwind]

Also I had a bike that I could NOT get any power on, did everything, cleaned carb, checked timing/points all that, but ended up being a clogged exhaust pipe. But idk how likely that is on a 4 stroke, mine was a 2 stroke, but could be something to check also.

[@darrinwoodward14]

Take some brake clean and spray around the intake manifold while it's running,sounds like an air leak to me.also,without the air box on it,it's going to run slightly lean,unless it's been jetted richer.

[@somerandomguy3868]

I recommend pineapple at times like this

[@twocvbloke]

If it isn't timing, and it isn't valve adjustment, it's likely still in the carb, or the union between carb & engine letting air in causing it to lean out...

[@yesnook7]

As for the weird idle, I it could be from a bad or a worn out needle, replace it and see what happens. ❤

[@chadbyrd3037]

I was thinking vacuum leak right before you said it. Spray starter fluid around the carb and see if the idle changes..

[@harleystock3447]

That's not a bad idea

[@Lee-At-Green-Pheonix-Rc]

The tuning on the carb will again be different with the airbox restrictions but does sound alot bett running no surging

[@89HondaCR500R]

its a float level issue thats where my money is

[@brantmcfarland517]

Yes me too and drove the needle too.

[@houstonhowell3618]

Had a couple smaller machines with similar issues solved with float level adjustments.

[@harleystock3447]

It does sound a air leak but it could also be the carb jetting isn't stock bc of the aftermarket exhaust that is on it

[@cabdriveruk]

Carb needs a good long clean in an ultrasonic cleaner to remove gummed up junk from jets.

[@dukesilver2019]

carb fuel leak or vacuum around the intake. Like an intermittent hanging idle. intake boot cracked or loose.

[@spaceboyrr]

Spray some soapy water around the carb and boot when its running to see if you are getting a air leak.

[@OrionJLRolen]

My first thought was float level issues, too low and starving for fuel when there is high demand. Gun it, fuel level drops too far too fast then it leans out.

[@mikecallahan734]

Try tuning it with an oiled air filter on it. May need back pelressure from the air filter.

[@Fireballsocal]

Good suggestion. I was wondering if the holes in the airbox were stock or modified. They were a popular mod, said to get more air to the engine. Taping em is a quick way to diagnose.

[@papabatsquatch]

The spinning of anything creates frequency and frequency travels throughout the universe. Everything rotated off a circle. Look around you, how many circle objects do you see? Spinning circles is it.

[@backyardprojects8153]

Check to see if the gear has moved on the cam shaft it's possible that it's off by a tooth or 3

[@wobblysauce]

From the first kickstart that backfired you knee to the bar, why haven't you just moved the bar out of the way when cranking?

[@finnenjr]

backfire = to lean. was what i have been thought.