How carb jetting works | Offroad Engineered

Let's be honest, who actually knows how to jet a carb? Exactly, very few... until today!
In this video you'll understand everything there is to know about jetting a carburettor.
If you need technical support, go to
www.stepstopodium.com/technic...
0:00 Intro
0:24 Anatomy of a carb
1:37 Jets and the throttle response
2:21 Pilot jet
3:14 Needle
4:05 Needle jet
4:43 Main jet
5:35 Tuning the mid-throttle response
6:19 End
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Cheers!
#carburetors #jetting #tuning

[@ryanshout8652]

How do we know if the engine is runnning rich or lean? what about a lotta rich or a little rich and vice versa?

[@StepstoPodium]

That's something that can only be understood with experience. Meaning that you actually have to start messing with the carb to understand what it means a rich or lean mixture. One great way to get a good base on that is to change the needle's circlip position to its extremes. That way you will be able to feel what is a rich or lean mid throttle response and translate that feeling to idle and full throttle. But nothing replaces getting your hands dirty and trying out :) With carbs it's a little more dificult to understand these feeling than with suspensions because you don't feel it in your hands (quite literally) but you feel it in the engine's performance. A lotta rich will for sure get you foul plugs and too lean will make your engine heat up rather quickly! Hope it helped 💪

[@ryanshout8652]

@@StepstoPodium Awesome thank you! I ride an older 4 stroke, 2010 yz250f, so it's part of the pre-EFI era and carb tuning is part of my maintenance. I have taken it apart, cleaned it, thrown in a JD Jetting kit that worked well. Then I had a buddy loop out (he's ok, so it was funny...) which bent up the stock muffler so I replaced it with an aftermarket pipe. Now I need to tune the carb a little... this info will help!

[@StepstoPodium]

Let me know how it turned out! I would love to hear your findings and how the video helped you tuning it 😁💪

[@user-tv6vy7rg4s]

@@StepstoPodium آ

[@akhileshkumargajendra2661]

If top of Spark plug (sparking area) is clear and white it is lean . If spark plug has carbon black carbon layer on top it means rich mixture.

[@neildxb]

This is the clearest explanation I have found for how carb jetting works! The graphics are a huge help. Thanks!

[@StepstoPodium]

Glad it helped! Thank you for watching 🙌

[@akhileshkumargajendra2661]

If Spark plug is clear and white it is lean . If spark plug has carbon black carbon on top it means rich mixture.

[@robhayter484]

No shit

[@DavidPerez-ci6qi]

Thanks I didnt know that unlike the guy above. If only someone had said that to him every time he learned something new..what a jackazz

[@robhayter484]

My 5 year old niece would have known that

[@DavidPerez-ci6qi]

@@robhayter484 I bet. A real born know it all says the jacksazz

[@robhayter484]

@@DavidPerez-ci6qi melt

[@csselement]

This is, by far, the best carb info video on KZbin (based on my research). Thanks, it was very helpful. What an amazing piece of engineering.

[@StepstoPodium]

Thank you very much! Hopefuly it remains so despite your ongoing research 😆 True indeed 👌

[@greyzoneofficial]

I would have to agree! Thanks!

[@greggfuller2220]

Absolutely genius by having the graphics. In jet pilot School they use graphics similar to this to explain jet engine blows and the operational systems of the jet. The carburetor video is well above any class I've ever taken. Keep up the excellent work, good sir!!

[@StepstoPodium]

Thank you so much Gregg! 🙌🙏

[@chandudammalapati2726]

Dude your video is one of the best that explains how a carb works.. You literally killed explanation... I don't know If I am going to rejet my carb, but your video really helped to fix my carb..

[@StepstoPodium]

Thank youu!! Really glad to hear

[@ultimateearrapechannel31]

for everyone who wants to know: a lean engine will be more silent and gives a slight delay at low throttle. so you pull throttle, and a second later your engine responds. a rich engine will have quick throttle response but gives bogging (on a 2stroke it is called 4stroking), so the engine makes a faster and louder sound, but the power decreases when its doing that.

[@jessejules2092]

Thank you

[@adeel.designer]

great !!

[@hhstarwars]

Why is it called 4 stroking? How does the engine being rich or lean in a 2-stroke change the crankshaft rotations? 😂

[@user-dq2fs8ed8e]

How do I fix it. It’s happening to me

[@hungkhan]

​​@@user-dq2fs8ed8eif rich lower the clip position until you the problem is gone, for the clean condition raise the clip

[@hardwaylearner]

best carburetor video on the internet

[@StepstoPodium]

Thank yoouuuuu 🙌

[@mikegentile13]

I agree. This explained sooo much!!

[@joliver81]

Having the graphic to assist explaining how are carb works was very effective. This may be one the best carb videos online. Would love to see another related to float bowls and there method of operation. 👍good job.

[@StepstoPodium]

Thank you! Glad it helped! 😄🙌

[@matthewryan2048]

Loved it, A good base line explanation without getting too technical. Keep up the good work.

[@StepstoPodium]

Thank you! 🙌🙌 new videos are coming out at the end of the month 😁

[@mjl8115]

This is the most niche YT channel I've subscribed. I love your videos. And this is another great content. Keep on doing yours Steps to Podium, Luis. Cheers from Poland.

[@StepstoPodium]

Thank you so much! I really appreciate it M J L! 🙌🙌💪

[@DIYWilly]

Great video! Straight to the point and really cleared up the questions I’ve always had for proper carb tuning. Graphics helped a lot!! 👍 Thanks for sharing!!

[@StepstoPodium]

Awesome! Super glad I could help! 😄🙌

[@guyonabike3828]

Best carb video I've seen on here, thank you, sir!

[@StepstoPodium]

Thank you so much Stan! 💪🙏 you have a bunch of other videos jjst as good 😄

[@derekrebel3384]

This really is a great video. All the info without overcomplicating things. Thanks.

[@StepstoPodium]

Thank you the kind words and for watching! 🙌💪

[@ryanmurphy9201]

This is by far the best video understanding the carburetor. Thank you so much I will be following you from this point on.

[@StepstoPodium]

Thank you! Glad I could help! 🙌😄

[@paivma8820]

Да, отличный видос получился! Однозначно лайк и подписка. Ваш фолловер 😂)))❤😊

[@traceprior2193]

You did a fantastic job on this video. Very well done

[@Camdouin]

That makes everything much clearer. Thanks

[@AntiStressKit]

Luis, thank you for continuously and consistently providing quality content. It is time to stock up on jet needles :-)

[@StepstoPodium]

I thank you for never skiping a video! 🙌 Stock up and have fun 😁👌

[@marcelsteinhauer4377]

Super easy explained and so clear after this video thx!

[@DJ_suzxki666_]

You made carbs looks like a simple device XD Thanks a lot :)

[@StepstoPodium]

Ah ah! Thank you for watching 😄💪

[@freedomforourfallen3755]

I’ve worked on carbs forever. This is a real good tool. I know to change things. So now I exactly what I’m looking at

[@StepstoPodium]

Glad it helped! 😄🙌

[@bansalartsagra3981]

one of the finest videos ever on the subject.

[@StepstoPodium]

🙌🙏🙏

[@jonathanredman8497]

Excellent video with easy to understand graphics. Thanks for posting.

[@StepstoPodium]

Thank you for watching!,🙌

[@Whammo77]

I think I just learned more about a motorcycle carburetor in 6 minutes than I have in the past 40 years. Thank you!!!

[@StepstoPodium]

❤️❤️🙌🙏

[@topstar3]

Yet another brilliant video! Great work my man!

[@StepstoPodium]

Thank you!🙏 I'm glad you liked it! 💪💪 onto the next one 😁

[@Jp11130]

Best video on how carb. Works Thanks

[@StepstoPodium]

Thank you!! 🙌🙌

[@danijuggernaut]

I´m not a beginner but i tell you this is the best video on YT for jet adjustement. See i power up my little 50cc two stroke to 75cc and i´m preparing well my first start. So people may thing on the first start you have to be cautious with too much rpm, but thats not true. Throttle up a two stroke means lubrication and thats what the engine needs at the first start with new cylinder and piston. But if you start up lean it can bring catastrofic consequences. So this video gave me the tutorial i needed. I adjust first needel to warm up the engine. To warm up we apply certainly one to three quarter throttle, so for that the needle is responsable and has to be the first adjustement. When this is ok i go for the idle by adjudting the air screw and jetting if necessary. The main jet will be adjusted on a longer ride with fully open throttle. Ohhh man, i got a plan, lol. Thanks a lot, greetings from Spain.

[@StepstoPodium]

Thaaank you Dani 🙌🙏

[@hellstrike007]

Good video. Really easy to digest too! Thank you for sharing your knowledge.

[@StepstoPodium]

Thank you for watching 🙂 there's a lot more on the channel eheh 😁

[@OFFroadOFFcourse]

Oooh, I hadn't seen this one! Brilliant as always! I learned soooo much, man!

[@StepstoPodium]

Just came out, don't worry 😁 thank you for watching and I'm glad you learned something 🙌

[@nigel2447]

Another great video. I am surprised by some of the negative comments. I just recently got back into bikes and two strokes. You gave an excellent foundational video. You are correct in saying it is time to go get your hands dirty, and I am sure guys can go do additional homework on tuning, plug reading, other means of figuring out how to dial in the carb. Also, being able to take feedback from the machine is critical.

[@StepstoPodium]

Thank you Nigel! True indeed 👌

[@philatwood2086]

Excellent video with clear descriptions and explanations... Yes.. you video is worth 10,000 pictures.. Thanks..

[@StepstoPodium]

Thaaaaank you so much! 🙌😊

[@simony5807]

Very helpful in visualizing and assessing my problem with adjusting my new nibbi carburetor. Thank you

[@StepstoPodium]

Glad I could help!

[@niconine268]

Great explanation, illustrations & summary

[@StepstoPodium]

Thank yooouu 🙌🙂

[@therealrealshocker]

Excellent video! Thanks for sharing! 🙏

[@shireproductions9499]

Great video. Thanks for the quality explanation

[@StepstoPodium]

Thank you for watching 😄🙌

[@vancezx11]

Very well explained.

[@endivas]

Mais um excelente video! Parabens e obrigado pela partilha!

[@StepstoPodium]

Obrigado eu por veres! 🙌

[@brandonfields4927]

Very informative! Thank you sir.

[@StepstoPodium]

Glad I could help :)

[@Theferg1]

Great examples and video and info!! I'm definitely a new sub!!

[@StepstoPodium]

Thank you!! 🙌🙂

[@JosiahNielsen]

This video helped me so much thank you😊

[@StepstoPodium]

Thank you for watching Josia! 🙌

[@stanbeattie3958]

Very good video

[@nunogens]

Great explanation! 💪

[@StepstoPodium]

thank you for watching Nuno!!

[@Dropsix]

Great video, thank you very much!

[@StepstoPodium]

Thank you for watching! 🙌

[@karlitosmanbur9153]

Thanks.... Easy way to understand

[@StepstoPodium]

Thank you for watching 💪

[@ningush24]

Great video! Tks 🎉

[@StepstoPodium]

😄🙌

[@RidingwithEthan]

Great video thanks for the easy explanatio ❤

[@StepstoPodium]

Glad I could help 🙂

[@guywy8310]

great video

[@chrisstokley7687]

awesome video

[@StepstoPodium]

Thank yoouuu 🙌🙏

[@medardocalumpag4108]

Thank you Sir

[@motoric5188]

Excellent video! 👌

[@StepstoPodium]

Thank you!!-🙌🙌

[@docteroperation]

Hugely helpful. Thank you for sharing this knowledge.

[@StepstoPodium]

Glad I could help! 🙌

[@sincityenduro4111]

Very good video, helpful 👍

[@StepstoPodium]

Thank you for watching! 🙌

[@Garage-gs5ch]

Mais um vez um excelente vídeo, com excelentes animações. Não esquecer também a afinação da boia 😉

[@StepstoPodium]

Muito obrigado! 🙌 é verdade, mas isso é uma afinação de manutenção e não de desempenho, que era o que queria incidir neste video 😉💪

[@nn-js4yg]

Thank you

[@ironDsteele]

Thanks for the explanation. Tuning the RZ500 is still a pain in the ass.

[@momentsoftriumph1050]

What a fantastic, clear video. Am new to this and looking to help iron out some running issues with 4stroke 50cc gy6 ped. Issues being slow to pull away from standing, can almost die. Also some bogging at full throttle. Also generally slow. First I'll just do a carb clean. I'll then see how it runs. Depending on how it runs.... Is the first thing to alter is the needle size? Or does it not matter, but only change one thing at once? Thanks!!

[@osimnod]

Excellent video and the graphics really helped clarify what was happening and when. Question: is there a practical way to test this without fully installing the carburetor into the boots? I suspect not.

[@AlexanderAfeldt]

Это первое видео где я смог проследить взаимосвязь между режимами, спасибо графикам. Я уже долгое время пытаюсь найти хорошую информацию по настройке карбюратора для своего VMAX 1200, все остальные видео представляет из себя в основном "бла бла бла". Спасибо большое. Если будет возможность хотелось бы видеть виддео подобного же плана, но уже с реальным мотоциклом и реальными настройками (желательно 4х цилиндровый). Что-бы можно было более четко проследить логику подбора. К сожалению не у всех есть под рукой стенд для точных измерений.

[@telo-cuento]

Gracias!

[@StepstoPodium]

De nada!

[@rroz4762]

Great tutorial ! I have been trying to tune my carb for awhile , 1985 XL 350 , installed a Mikuni carb and mid and top end , after some rejetting are doing well , my issue is with the zero to 1/4 throttle , when riding it fluctuates too much , constant variation up amd down , choppy i guess might be the term , thoughts ?

[@NirHason]

I didn't watch it but I'm sure it's going to be gold.

[@StepstoPodium]

Thank you for that trust! 🙏🙏🙌🙌

[@AntiStressKit]

Nir, I watched the video and can confirm - it is pure gold

[@StepstoPodium]

🙏🙏🙌🙌 thank you Ariel! I really appreciate 💪 onto the next one!

[@ericbenavidez992]

Best explanation 💯 Question: have a straight piped Honda shadow 1100 that hasn’t be rejeted and I’m in the process of it. How should I rejet it? In idle it’s to boggy and when I’m in mid rpm’s I have to give it more throttle

[@ville5152]

higher the needle!

[@freashtoast1684]

Legit exacly what I was looking for at 3am

[@chrismalton1904]

Great video thanks. Just a question if that's OK. When travelling down hill on my 2 stroke Beta Xtrainer 300 with the throttle fully closed I get a lot of surges, so much so I often pull the clutch in. What's the cause of this. Many thanks Chris

[@greiner7414]

Great visual thank you!!!!! How about a O2 sensor for measuring air/fuel mixture as a tool?

[@StepstoPodium]

Thank you for watching! 🙌 It can be used, for sure 💪

[@ricardobh2979]

Show de vídeos muito bem explicado

[@StepstoPodium]

Muito obrigado Ricardo! 🙌

[@emeraldviking3637]

Super Trooper 👌

[@track1219]

Good video! Also a float level set too high will make engine run rich.

[@luiscarneiro1669]

Excelente!

[@StepstoPodium]

Muito obrigado Luis!🙌

[@anandblore10]

I have installed bigger pilot jet and needle lowered to 2nd position but there is light sputtering apart from that performance is very good. So due to sputtering I lowered needle to 1st position and sputtering stoped but less power in middle throttle position.should I change the larger main jet to gain more power or the larger needle to be installed with the circlip positioned to 2nd or 3rd depending on the performance Thanks

[@akhileshkumargajendra2661]

You can adjust carburetor niddle up and down. It will give rich or lean mixture depend on niddle and fuel mixture screw. Niddle setting gives best acceleration response.

[@RwP223]

Heck yeah, needle is a big deal

[@ArcanoDCUO]

Mine is always bogging if i pull to fast... i tried everything...

[@lukaszobrebski4440]

My four stroke Yamaha 90 must be on quarter choke otherwise stalls. Would bigger jet hole help with that. Thanks for help

[@marcellogarcia]

Very good 🇧🇷👍🏻

[@StepstoPodium]

Thank you Marcello! 🙌🙌💪

[@stevesherwin1]

The bikes not picking up on low throttle fast enough what jet do I need to change bigger or smaller?

[@kings17court]

My 4-stroke bike starts pretty good cold. Sometimes 1st kick. But when it warm, it's hard to start, and it starts most reliably with half choke. What does that sound like to you? I'm thinking maybe the main jet is a little to big, or a little too small?

[@_.R.F.X.L._]

Will help if i change the mainjet from 0.82 to 0.99 and the atomisor with more holes to mixt more air?

[@ACommenterOnYouTube]

So ... On a car we have an 02 sensor or wideband O2 sensor to monitor its af mixture, HOW do you know how lean or rich it is on a motorcycle to know if you need a smaller or bigger jet or needle ??

[@coyoteserranoband]

Are both jets supposed to work at the same time? For a 2 bbl? Or is one a idle jet and the other a main jet.

[@TheHeshgoodman]

I have a 2002 blaster and I took off the air box lid and I was told to re-jet my carburetor my main jet is stock when I re-jet do I go up in size or down in size

[@dennisday1023]

I have a 50cc 4-stroke scooter with a pz16 carb. Had a little trouble with idle, switched the stock 35 slow jet for a 38 and now it idles fine, and the mixture screw reacts like it should. It runs fine all the way from idle through almost full throttle. At full throttle it loses power. Doesn't backfire or die, just a a slight loss of power. If I back off just a little from wide open, it runs better. I'm thinking I need to swap the stock 75 main for a 78. Does that sound like a move in the right direction? Thanks for any info!

[@threewheelerdonuts8284]

Great video! I assume that air temperature also affects how you jet your carburetor as well

[@StepstoPodium]

Of course it does!

[@mimrans41]

Hi great movie,when my bike cold and even warm it sound stable,when it get hotter the idle rpm get upper and not stable.what do you think should I do?

[@ricr250]

Como sempre, as animações são do melhor que podemos pedir! 👌 Varias marcas tem no manual uma tabela com recomendações conforme a altitude/temperatura a que andamos na mota. Bastante útil para ter um ponto de partida, pois por norma são sempre um pouco mais ricas, para salvaguardar o motor. Melhor trocar uma vela, que o pistão! 😂 Ja agora, na gasgas que tinhas, que setting usavas para hard enduro? É que a tabela da gasgas é para esquecer.... e melhor nem falar da agulha de origem!! Continuação de um bom trabalho! 👌💪

[@StepstoPodium]

Ora nem mais! Em relação à minha gg, já não faco mesmo ideia 😅😅 Muito obrigado Ricardo! 🙌🙌💪🙏

[@Pitter_crewzz]

So what do I do if it only gives power at full throttle and bogs otherwise it will sit and idle nicely but if I’m riding and wide open then letting off to get back on the power it will bog until the last quarter of the throttle twist

[@edza_lol]

I have problem I can start my bike and its runs but when I give full thotrle it stops runing what I need to change ignition is good I can't understand the mixture is lean or rich help me pls.

[@JamesMcGraw-ph1el]

What should i do if im starting to bog a little at full throttle but when i play with the choke the bike picks up again

[@alexp.6406]

How do you determine if it’s too lean or too rich at each stage (idle, mid-throttle & full open)?

[@xt225]

Great video. Would have been perfect if went through the air/fuel mixture.

[@r_s_enduro]

What about thickness on needle for hot weather? Hot and dry.

[@Johnny_OSG]

Ohh, that part about needle jet & needle combo was good. I have problem that I raised the needle a lot and my afr is still to lean in the mids. Does that confirm that I need new bigger needle jet and needle? I'm running zzr1100 carbs on bmw m10b18 engine so there is little info on tuning from scratch

[@StepstoPodium]

Probably!

[@Billy_the_Wolf]

Bigger main jet or tight needle jet ?? 🤔 Please help i have a ZX6R 2002 runs good in idle but it need more gas in mid and high throttle

[@vladdehtyar7535]

Hey Thanks for the video 👍🏻 My bike seem to have a delay in dropping the rpm after I let go of the throttle while riding , Is that too lean or too rich mixture? It also seem to overheat a bit

[@StepstoPodium]

Definitely lean

[@Steveman61]

Great video Luis, just one thing the needle jet is mounted into the jet block, not the slide ;-)

[@StepstoPodium]

Fair enough steve 😅😂

[@Pain-bf8mr]

HELP! Today I straight piped my motorcycle and as I was riding I would hold the clutch in then my motorcycle would be so quiet as if it was off. It turned off once.. so my question is what could be the problem and how to fix this Thanks!

[@martymyers3018]

I have a 2009 yamaha 250 .4 wheeler .put new carburator on it and new jets .how do I adjust the fuel air flow valve . It cranks idle good but when you put it in gear it want take gas .it dies

[@hotchihuahua1546]

The number one reason customers came to my shop . A clogged pilot jet on a carbureted bike . First indicator ! If you need to partially run your choke once the bike starts and it won’t idle well with the choke off . Do that enough and you eventually foul your plugs . Know the first signs !

[@ArthVader09]

my only problem is full throttle feeling. when 0-80 kmh is fine but when full throttle, 80-100kmh feels slow to reach top speed. do i need rich or leaner main jet?thanks

[@markhodgkinson151]

Honda XR400R done 4000km and was getting difficult to start Once started it would only run on half choke. So I bought a rebuild carb kit with all the needles and rubber rings. Hex Main Jet - #140 Slow Jet - #52 Jet Needle - D625 Fitment: Fit for Honda XR400R 1998-2004 Cleaned that carb like a new pin. Fitted the new parts. Paid attention to the original screw settings. Starts easily no choke. Open it up it dies. Put half choke on it just about let’s you open the throttle but doesn’t like it. Put full choke on and can open the throttle and drive about easily. What have I done wrong and what do I need to do?

[@shkelqimsylejmani1835]

in which part it should be decided that the engine has more power thanks

[@GuillermoVargas-gm5tu]

what if when i go from full stop to full throttle and it bogs down what should i do