Can A Dirt Bike Carburetor Wear Out?

Analysis of the wear points on a heavily used Keihin PWK Airstryker carburetor. I suspected this carburetor was worn out because the motorcycle it was installed on (Hard Times) ran extremely rich despite proper jetting and adjustment. This style of carburetor was used on the Honda CR250, Yamaha YZ250, Kawasaki KX250, Suzuki RM250, and many other 2 stroke dirtbikes from various years.

[@hulashark6525]

Really liking this quick turn around, love watching you two. Keep the videos coming. ✌

[@miguelpagansr6128]

I had a similar situation on my carburetor on my Honda express2, and I noticed that the carburetor jet is not removable from the factory. So what do you do when the needle and jet are worn? I’m thinking of buying a new one and see what happens.

[@gregmathews1369]

This video sheds great light on an entire lifetime of rebuilding carburators and not understanding why certain carburetors still do not run right after rebuilding. Thank you very much for telling the time to solve one of the greatest mysteries known to the backyard mechanic.

[@bigjoe2277]

Why aren't more youtubers like this!!!!! Genuine and authentic

[@codycarse]

“This isn’t a carburetor KZbin channel” sir I think you should go count your videos that feature carburetors vs those that don’t lol 😂

[@Nevir202]

HE: Reality can be whatever I want!

[@cobravello453]

pretty much 100% of his videos feature his nose but that doesnt make it a nose channel...

[@HITANASG1]

​@@cobravello453or does it? *Vsauce music starts playing*

[@codycarse]

@@cobravello453 🤣

[@AndrewWilsonOz]

Carbies do wear out. Anything that has something moving, or moving in it, it will wear. You can't cheat physics. Thanks for making your videos. :)

[@wobblysauce]

Have to admit I have never seen one as worn as this one.

[@CodeOptimism]

Funny you thought this might be a dull video because I actually think it's one of your best. 😉👍

[@noyopacific]

Jake says he feels kinda silly. I can't imagine why. He is always so earnest and reasonable about everything. 😜 Thanks for the video Jenny& Jake !!!

[@jake360flip]

My eyes and ears are being blessed with frequent content. This is glorious.

[@2006rm250]

One of the main points of wear in those types of carbs is the emulsion tube (the part where the main jet needle slides up and down in) where it almost always gets over looked. People always go to the float needle and clogged jets. The slide itself as you’ve shown also 100% does and can wear out causing issues. Carbs can get to the point that not even extensive rebuilds can fix, because the body where the slide is eventually does wear out.

[@tonyz2897]

While watching the video I was wondering if a new emulsion tube and needle would fix the excess clearance and get the old carb working correctly.

[@LocalCelebrity412]

The float pin hole is all wallerd out

[@keshmo12]

I had an xr 250 carb with a worn out needle tube thing. I "rebuilt" the carb and never put that little tube thing in because it looked annoying to replace and and it didn't run great. Took it apart again and replaced it and it was much better.

[@kriswright1022]

​@@tonyz2897On this type of carb, its called a needle jet. And it does , indeed , wear out, as does the needle.

[@chebbyshev2204]

I don't know if the humor in your vids is better or the mechanical knowledge that you share. Love the channel even if you are doing less editing and perfectionism. I can't tell. 👍🏼

[@StraightLineCycles]

worn out needle bore, you are a genius sir.

[@krisley5178]

That was simply great! There's a tip on carb's that I have never seen before. Excellent work Sir!

[@dougharder6258]

Great video! It is really not a choke, it's an enriching valve. A choke covers the intake chocking it off causing the vacuum to draw in more gas.

[@CodeOptimism]

Thanks for this comment. I was questioning what I knew. 😅

[@HITANASG1]

No, it causes it to draw in less air 😅 with an enriching valve it draws in more fuel

[@dougharder6258]

Agree it is less air but it also draws more fuel. Ever use your hand as a choke. @@HITANASG1

[@timwilliscroft9615]

The choke lowers the air pressure, which encourages the fuel to vaporise better at lower temperatures.

[@HITANASG1]

@@dougharder6258 I have but I don't get your point. It's simple less air coming in for the same amount of fuel = richer mixture

[@user-zh7zj8cw2i]

This was so interesting! I had no idea that the wear could be like this. Great job explaining and showing this. This hiccup at the end makes it all the more entertaining!

[@sandqwert]

It's nice to see regular videos once again, glad you are back (or back-ish).

[@johnbest4320]

ive watched every video that you guys have ever made this is my first time commenting loving that your back making content your videos are so positive i really enjoy your bike content i hope you continue to keep uploading videos you and camera girl do a great job much love

[@MainelyMoto207]

every time I see a video from this channel I get so excited! LITERALLY my favorite channel

[@tlwayman]

I like all the videos….PLEASE keep it up this time lol

[@Kiwi.Fix.It.144]

I AGREE WITH YOU COMPLETELY. I had a 98 xr100 with the same problem. I changed all the carbies internal components and it didn't do anything. Replaced with a new one and it reved fully after that. Wish I kept the old one to test it like you have done. Thanks fro NZL

[@WWNF911]

Lovin all the content lately. You guys rock!

[@Davojo]

They're back!! Thanks for uploading more! Always enjoy your content!

[@Davojo]

Interesting video aswell!

[@506curtis]

I do infact surround myself with old worn out things. Love your videos.

[@johannesversendaal4554]

A pro with a perfect ending. Great job you two, really enjoyed this one.

[@OldManJenkins23]

cranking out the videos dude, love em

[@Scooter30FTW]

Well,I believe Jacob showed that carburetors can in fact wear out.

[@TBone-yc6zg]

You need not use a drill on the "don't take me out" screws. You need only go to your Internet and order a set of security torx bits. I got a set from the local Harbor Freight.

[@WWNF911]

I have the same set although you have to thoroughly inspect each kit. The Chinese bits are not as quality controlled and if you look at the bits they are NOT all the same. Inspect the dot inside the security bit and some (more than makes me comfortable) are not in the center but are offset. Just have to inspect and be careful .

[@VashStarwind]

That was just a joke haha

[@89HondaCR500R]

probably one of the most informative videos to date good work guys slap hands!

[@jameshilliard7576]

Love all the new content!

[@Bill-es8ds]

Great video, Don’t sell yourself short. That tip over happens to lots of us.(shit happens) you could have edited that out, but u didn’t.Anywho, technically the carburetor didn’t wear out, the parts in the carburetor whore out. That pin is probably not the original one. Someone probably lost it, and put a pin in there they had lying around.those pins don’t shrink due to use.love your video’s brother. Keep them coming. 👍✌️

[@AAEmohawk]

You know then he put the pin into old carb he did say that was the NEW pin not the old one that went ALL THE WAY DOWN. So it was the hole was was now to big as well. not just the old pin that was damaged.

[@Bill-es8ds]

@@AAEmohawk I think you r talking about the needle pin. The pin I was talking about holds the float in. But what he also said that some people like to drilll the carb holes out , like the Jett’s u can’t trust what the size it says on the Jett, because someone may have micro drilled out the Jett. Who knows what was drilled out and what was just wore out. Anywho- the other carb made the bike run great.

[@philrc1]

Very informative and fun to watch. Keep it up.

[@webstella]

I learnt this lesson a couple years ago. I have an arctic cat zr800 snowmobile that I was fixing up. PO broke tip off the fuel mixture screw for the idle circuit in the body of one carb. They are flat slides. Went and bought a used set took it apart to replace the body on the one carb. Unbelievable amount of wear. My old set looked virtually new compared to this set. People are always talking about slide wear but thats not where the majority of the wear occurs. Most of it is on the body itself. Specifically the runners which the slides run up and down on. Then it will leak air like crazy. Finally got lucky and got a used set cheap that wasn't completely worn out online. Easy way to tell with these flat slides is to shake them. If the slides rattle like crazy forget about it. My original LIKE NEW set was virtually silent when shook. The first replacement set rattled like a tambourine. Really a shame about the fuel screw. Can't blame the PO too much though. The fuel screw has such a fine tip on it and the spring you are screwing against is quite strong. I managed to figure out a way to set it so I am guaranteed not to break the tip off by counting how many turns it takes to get the screw to stop without the spring on from fully unscrewed. Then backing off the appropriate amount. Wish they would have stuck with round slides though. They last much longer than these flat slides. Damn the negligible improvement in throttle response.

[@kriswright1022]

The round slides can be honed out to over sized and sleeved, my old Triumph 750 has the round slides

[@jeffreygortz6146]

Ive been working on dirt bikes for decades , thanks to you two , " an old dog can learn new tricks , your channel is awesome ❤❤❤❤❤❤

[@unitedstatessc]

This is my favorite carburetor youtube channel.

[@chadriddle3517]

Excellent content !!! I’m having issues right now with a rich condition on my 2000xr100r. Oem carb was trashed I rebuild it all except needle collar seat and needle and this would explain why rich conditions continues! Ty I can’t wait to swap the needle and needle seat an see if That corrects it . Always love yalls content genuine down to earth folks !

[@austinbarnett9511]

Camera girl is absolutely right! No need for any excuse for what you want to make a video about! Very interesting video, who knew carbs could wear out!

[@blakey271able]

I don't have a bike because my finances don't allow but because of that I do enjoy watching these videos and learning for when I can afford a fixer upper

[@zeighe4097]

Love the recent stream of video activity. The wife and I love sitting down and watching you and your wifes adventures. Keep up the great work, your videos always brighten our day. ❤

[@conebone669]

Love the video. Super helpful of carb diagnostics!

[@clarkwilson2670]

Regular uploads have been awesome!

[@supertedogpriken]

You are 100% spot on. I have seen this happen to a few bikes. It is usually the "forever" bikes that gets this kinda problem. i have seen it on Suzuki RMX, Kawasaki KDX and Gas Gas bike. The kinda bikes that just keeps on goeing and going and going. Way longer then any other bikes out there. And when the bike(s) just keeps on running the throttle gets twisted and the carb gets worn out. And i have argued with so many people because just about everybody thinks it`s the gasket "inside" the carb. Love all these videos you guys are posting. And love all the Gas Gas content even more. Cheers, and greetings from Norway :)

[@primodeelux]

Dude…..you’re awesome. I was surprised to see the new needle go into the old carb and see it not seat. I’ll definitely be including this as one of the items to regularly check when rebuilding carburetors on my various toys. Good detective work.

[@proudpennsylvaniaman7996]

You guys are so cool. I wish you posted more. But also love the mysterious nature that comes along with the random post dates

[@pecak]

Thanks for the vid! Oh man... I called the needle (kind of) under the previous video. I was talking about a worn out emmulsion tube (also called needle jet). Was reallæy hoping to get noticed :) I am really happy that you managed to fix the bike.

[@brettknibbs9351]

You can just replace the emulsion tube and needle

[@martinhall5980]

My favourite KZbin channel bar none.

[@Idatech7]

You are my absolute favorite KZbinr- hands down. So awesome to see you again. Thanks for the great video. Very good findings on that old carb.

[@clashbrothers8967]

This helped me so much, having carb issues with my old yz250, THANK YOU SO MUCH

[@patrickkirwin5832]

I appreciate the simplification of your videos. so many people get so into the weeds with their videos. you should try to put out more content if possible, I find you two refreshingly entertaining. for as few videos you put out, you have alot of subscribers. compared to other channels. good job and good luck.

[@somerandomguy3868]

I think you've done a great job, I've never seen the float retaining pin do that before, hard times has really come along way, maybe you can start calling it good times

[@adrianpancaldi8646]

Thanks for the intuitive vide and also leaving the last scene in, it helps people feel normal!

[@yourface3154]

Holy shit pumping out some videos, we're here for it.

[@theneuls4922]

Always happy to see a new video coming out ❤ Its a great one too. I currently can't work on any motorcycles but with your videos I feel like I'd be standing in my garage and figuring out the problem myself. And I'm learning a lot as well! So thank you and keep up the good work!

[@chadbarton3235]

Great video. The needle and tube get overlooked all to often. I find this very helpful for my snowmobile carburetors as well. Having over 30 carbs to keep clean, I'm into some every year.

[@tomdunn7147]

I think that was a great video. I am sure this will help someone else diagnose a problem they are having. Keep the content flowing.

[@AllenSpeck]

Great Scott! Excellent find team, Thanks!

[@ErrtuZarathos]

Very informative video. also jets does get sloppier with time.

[@Ironsights85]

really enjoying the more frequint uploads!

[@colintichenor828]

Loved this video. Very informative on an issue not well known about. I watched your old KDX250 video that had the same problem and I used the knowledge for my KDX. Love the videos!!!!

[@rigguyjt]

I had mentioned the needle in your previous video. I was certain that was the problem. Glad you checked.

[@SuperHurdman]

Thanks Jake and Jen I am working on my snowmachine which I left sitting two years as last winter I lost the snowmachine in a snow bank lots of snow I went home to my Mothers and when I came back I wasn't sure where it was until march when it appeared regardless I have carburetor issues so off to the dealership to get new parts tomorrow! Always great to view your videos thanks for showing! Marc Gagnon

[@foxpuremage]

I too was very interested in this video, apart from the times where I was bored

[@RockAnAhardSpot]

ALWAYS AWESOME GUYS! this video was great, seriously, I cannot remember how long it;s been that I have been watching ya'll but i feel I have gotten older so it must be a fairly long time. i watch a lot of vids while working. I think this channel has made me a better person in the way of , I am not the only one these things happen to. LOL.

[@chihuahuaverde425]

Nice video. I rebuilt a Mikuni TMX carburetor (no block gaskets, basically a chunk of aluminum) and had months of issues, and finally gave up on it. The bike came with an extra used carburetor which also had months of issues after a rebuild. Basically the bike would die with any amount of load placed on it and spooge everywhere even when jetted extremely lean. I got a new carb and no more issues. I think you are correct on the carb wearing out. Also consider particles in fuel and dirt getting past the air filter basically wearing down the passages.

[@gisch_racing]

Thanks man ! I never thought about that. Although im working on bikes(just for hobby) for nearly 10 years. Awesome !!

[@petewg56]

Great video... you two have a great sense of humor...I always get a chuckle and I thought your carburator presentation was great!...the bike tipping over was a bonus... your reaction was great...please keep the videos coming!.. Thanks!*

[@madestman101]

Big Hello from Australia! Thanks for the videos. I watch them more so to see you guys, so even if it is carb vids then it is great. have a great week.

[@reckless3008]

So glad to see videos coming in❤ your my go to KZbinr for fixes i have the same love for all bikes an machines as you guys !!!

[@aidanrussell-smith4619]

I love yalls videos so much always a highlight of my day loving the quick uploads

[@alexwirtz3047]

In the snowmobile world, it’s very common for the float pin bosses to wear out on Keihin carbs. This will result in a rich condition because it slightly adjusts the float height. Even if you adjust the tab on the float, it will always be out of adjustment due to vibrations. The Mikuni carbs don’t seem to have this issue.

[@Spartan375X]

Amazing problem solving as always! I work at a place in the fall, scaring and chasing people around with a chainsaw. Since I'm one of the most mechanically knowledgeable people with that chainsaw model, I have fixed up quite a few with the carbs completely worn down, some with the shaft that the flap sits on barely hanging on by a thread.

[@ktmroby4479]

Yep it just wanted to be smack over lol. Sounds so great, hoping to see you ride it. Camera girl is great as always. You guys still remain my favorite since I was looking up a bike I had which was a 2002 yzf 426 that should say how long I have been loving every video you do.

[@TheProCut17]

thanks for the lesson, carbs are a weakness of mine. so the more I can learn the better.

[@markosaarela3537]

This video was very educational and i learnt new things. I may not need this knowledge now, but im sure some time on the way it will come handy.

[@toralfcross3819]

I would have to agree with the old carburetor guys and say all your findings are repairable however those are all very good findings that you have made inspecting this carburetor.

[@leviphillips1589]

Great video, some (me) may never think of this. I’ve been dealing with a rich condition on my rm125 no matter what jetting. I will investigate. Thanks and great video

[@peteremilius7314]

Great Vid and i agree that carbs will worn out cause they move in many parts. Mostly slides and needles with valves. That is my reason in more than fortyfive Years of maintain my old bikes. Y apreciate to use the service of Keyhin, Dellorto and mostly Mikuni carbs here in Germany. Thank ya for your Experiance.

[@sidneywright4466]

Loving the more uploads!!

[@pinarrioqwer2933]

Ohh yeah, now it sound as it should! Great video, as usual!!!

[@nct9466]

Drilling jets bigger or even soldering up a jet n redrilling isn’t uncommon in the past. Perfectly good way to tune carbs!

[@nct9466]

Also the “metering tube” where the needle runs wears with petrol passing it etc eroding it bigger - not uncommon on some carbs

[@carlitosbrigante6889]

Can’t wait for this lovely couple to try a smart carb / lectron carb one day.😍

[@mattcole2863]

Love your videos! I've been watching since the lowes return generator!

[@jenniesgarage]

Glad you like the videos!

[@noscil9403]

I just love you two

[@gaillaffer7579]

Love you too. Such a great combo. Thanks for another great video.

[@454Burban]

Just to prove that I did not find this video "stuffy", I've watched it TWICE, back-to-back... while rebuilding a pair of Mikuni's from a Yamaha XVS650.

[@GaryLordsWayMinistry]

Carbs can and do wear out especially where rods wear on bushings for throttle positioning and even choke levers etc. Jets not so much as long as you keep drill bits out of them and are careful when cleaning them. But dirty fuel can increase in diameter wear of the jet if there is enough dirt and crime that keeps going thru them. Bound to make the hole bigger with time. Even float assemblies will wear out. I concur on your assessments of wearing of parts. I see a new purchase in your future unless you can apply some heat and bend it back. And you know darn well what I am talking about too. Maybe even a new video of straightening out a bent clutch lever.

[@mikespain8655]

Good video. It takes a lot to wear out a carburetor, but that old one was worn no doubt.

[@jameshisself9324]

Can they? They always do! The question is does the design allow for proportional changes so that the slide to body air leakage matches the needle fuel leakage. Roughly. Mikuni and Keihin are pretty good at that, Amal, Dellorto and others often are not. A new carb almost always works better on older bikes (which are about the only carb bikes these days) especially if the air filter and pre-filter were not maintained while riding in a dusty environment. Most neglected bikes were not.

[@ErikSeastead]

I had a certified Hondaechanic rebuild the top end of my 2004 CRF100 back in 2020. One of the things he did was buy a new carb because the fuel corroded the walls where the float needle sat to the point that the float needle wouldnt always move freely. Carburetors were not made to soak in caustic chemicals for many many years, which my poor dietbike did when i moved to suburbia for a decade.

[@libertyforamericanow]

Good job on the vocals

[@Chong1975]

Love the explanation. Carburators were always a problem for me...

[@leftyelomis1824]

You're such a wholesome content creator. Do you find online the service manual of your motorcycles before buying them?

[@Mounta1ngoat]

My carbs were inconsistent, pulled them, stripped them down, needles out. One of them had 4 slots for the circlip, the other had 3, with one very long slot where the vibration had caused the circlip to wear away the needle, and the circlip was freely bouncing around adjusting the needle height at random.

[@mrshaneyt43]

Great stuff 👍 loving the regular vids

[@overloadedoutdoors7582]

Keep the videos coming I enjoy watching them

[@kayakchrispy]

Now I understand something Thank you for making the helpfully dull video .. 😊

[@user-st8sp3fw8h]

perfect video for the subject/context. great ending too :)

[@4STEVEJOY34]

Great tip. Excellent investigation.

[@captsam54]

Awesome.. easily the best Loved Channel on You Tube... A Shot of Jennies garage is aways inspiring... (hairs looking good too a little longer)...lol

[@jurajkovac1770]

my neighour have had this exact problem with carb, great video, love to see more diagnostics for example ignition :D

[@randyjude8346]

" Have you ever done that? " Earned you a solid thumbs up!😂😂 Cause oh I ( we ) certainly have!