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 💪
@@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!
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!!
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.
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..
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 !
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.
The animated diagrams in the video are top notch. Even though i knew how the various circuits worked, it was helpful to see the visuals to really make everything click. Great job!
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.
Well explained and very informative video with graphics to understand better. I hope you make another video for the best setting to get higher fuel average.
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!!
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.
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.
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.
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.
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 ?
The way to set it is to look at the color of the spark plug after the motorbike engine is running... if it's wet or black it means it's wasteful, if it's dry it means it's economical.
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.
correct me if Im wrong,,, the pilot jet supplies fuel all the time. not only when the throttle is closed or partially opened. so the pilot jet can be used for very fine/final tuning.
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
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
Look at your spark plug if the tip is white or gray then it's too lean and you need to up the Jetter raise the needle and if it's black and oily then it's clearly too rich and it's choking out the motor
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!!
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?
Hi Thanks for the video! I have a problem with a hanging idle. When i start the bike it just runs normal but when i give it a hand of throttle the rmp stays high and wont drop. When i pull the choke out and right after i put it back in it lowers down to the desired rpm. When i ride slow technical stuff and pull the clutch the rpm rises again and only drops when i let the clutch out. What do you think the problem is? i ride a crf250x
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
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?
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
Personally for me the way you explain is Golden mate You should teach school teachers how to teach kids. if you were my school teacher I would had learnt something and not left at 14 🤣
Thank you so much William!! 🤩 I really appreciate hearing that from you 🙌 It definitely helps the channel grow and helps me produce more content like this one, so I really appreciate it 💪💪😊
Any one have any idea what could cause the engine to sort of stutter at wide open throttle? I have a honda xr125l and if you change gear and try to accelerate fully the bike sounds like it's redlining and then suddenly accelerates
