How to adjust idle on 2 stroke dirt bike - air screw adjustment 2 stroke. 

People like you are why everybody loves the biking community simple explanations and best accurate tips that actually help

This vid should be a reference point for everyone tuning a 2 stroke. Simplifies it all.

Best tutorial I've found so far. Thanks man!

This video on two strokes taught me more about tuning a 4 stroke than 7 other videos I watched on 4 strokes before this. Thanks you for differentiating the different types of screws and being specific instead of just throwing the same term around over and over

Dude I'm seriously surprised you're videos don't have more views they're super informative , I just picked up an 03 KX100 and your videos REALLY help man!

Thanks for explaining how to actually adjust carburetors instead of going into a 35 minute video explaining how to build one from scratch if ever everyone on the entire planet dies out.

I must admit I adjusted the idle on my Yamaha yz125 by the cable, I did know it was not right to do it that way but I was too frightened to mess around with the screws on the carb in case I messed it up and couldn't put it right but after watching this video I'm no longer frightened and am going to do it the correct way tomorrow. Thank you for explaining it in a simple understandable way.

This is a nice, basic explanation of how throttle stop idle screw works and the idle air/pilot air screw relates to it. Thank God this guy did this

So easy to understand, never played around with carbys but this has helped so much with such a little adjustment. Thank you

A truly solid foundation for new 2 stroke owners. THANK YOU!!

This video saved me time & money! I took my dirt bike to dealer to get inspected & after watching this I was able to do it myself

Thank You, I put a new carb on a 71, CT175 Yamaha that hasn't run in years.. (Haven't owned a 2 stroke in 30 years) Helped me out alot!

I remember just 3 years ago when I got my first bike and watched your video and not knowing anything and now I repair bikes for people I know and friends

You are good men! Gretings from Poland!

Very good information about this. I believe that the biggest problem is people will do this only when they have to. Not very often so it's forgetting how to. But then again, they don't have to with videos like this one. Thanks for sharing this

Thank you for your input. My son's bike was running like crap. I got it running a little better but after watching your video I was able to get it running great. Thank you again

Best tuning explanation I’ve heard to date. Well done!

Great information Rado. Wish I knew this 10 years ago, I adjusted my idle on 2006 Cr250 the wrong way! Had a flashback watching this video! Enjoying your vids.👍

I watched all kinds of confusing videos on this you are the only one that I learned something from and got my ATV back on the road Thanks.

Great video. I battled with idle on a 2021 kx85 for 2 weeks. This video helped. I turned in both idle and air screw and started the bike and continued to turn down the idle until the bike quit. Started again and turn ed air screw out until there was excellent throttle response.

This has been already said, but this is the best 2 stroke jetting and idle video yet!

ABSOLUTELY BEST TUTORIAL YET FOR A NEWBY LIKE ME !!! THANK YOU FOR YOUR TIME AND THOUGHT INTO YOUR VIDEOS!!!

Quite a library of useful information you've put together. This video was EXACTLY what I was looking for. In your "I was wrong about the YZ125x," I mentioned that I was on the verge of getting my son a 2-stroke 85. When I bought it the bike would not idle. I felt confident that it was something simple, because it would start first kick (as long as you gave it a little throttle when kicking it over), but it would not idle. I didn't have a screw driver, so I tried with my fingers, but it was too tight. I bought it anyway. When I got it home, I set air screw out to the "starting point" of 1.5 turns out, and with adjustment of the idle screw, I achieved a pretty good idle. The only minor issue I have is that once it's idling nice and low, it kinda bogs a little when you blip the throttle. Once it revs, and you let go and re-blip the throttle it's pretty much perfect. But when you let it do the nice low idle again, and blip the throttle, you once again get that initial bog. This video has made me hopeful that if I play with the air screw, I might be able to get rid of the initial bog off of idle. Thanks.

Most helpful video I've found yet. definite thumbs up, thank you very much! got my first ever 2 stroke today (04 CR250) had this exact issue with the idle due to change in elevation and before I saw this vid I couldn't figure out what was going on with the carb. I had people literally try to tell me my bike had a bad crank seal lol.

Thank you so much. I just got a 2022 ktm 150, and I’m getting back into riding. I knew right away the throttle response was off, but I couldn’t tell if it was fuel mix, jetting, etc. this helped!

Straight and to the point. Great explanation, my bike boged a bit and wouldn't idle on its own.now after tuning my bike like he did it runs great now.

Honestly, I find that tuning purely by ear will often lead to being in the ballpark, but not quite. I always like to run a tachometer - even a 5€ one will do - and zero out my settings. I will then pull out the air screw two and a half turns and three or four on the idle screw. That will usually get any bike going on a lumpy idle. Next I tune down - or up- the idle screw until I get something consistent at, lets say, 1500rpm and only then I start playing with the air screw. Screw it in a quarter turn and see what happens. If the idle goes up, then I'm in the right path. If the idle goes up, then I bring the idle screw out until I get a steady 1500rpm again. Wait a few seconds and give the air screw another quarter turn. If the idle goes down, then take the air screw in the opposite direction. Do not adjust the idle screw to compensate a low idle after a tweak on the air screw. Repeat until the best possible idle is achieved. From there, I will always screw out the air screw an 1/8 turn, just to keep things on the rich side and add some response. And that's about it. The over 3 turns, under 0.5 still apply, but this way you can be analytical in the process if you're just starting out and visualize the results of what you're doing. On four strokes I pretty much do the exact same thing. Tuning an idle on multiple cylinder carbs. Now that's a bit of a pickle :D

Best video for air screw/idle tuning 👌

Thank you, just rebuilt my sons kx 85, and you have helped me 100%! Much appreciated!

thank you! This video was super helpful. You helped me get my 1976 YZ80 running, it was jetted way off after getting a replacement eBay carb for it. now it idles great!

Best channel ever about pitbikes

Brooo! Thank you so much! I’ve got a 2021 YZ250. I took out out for my first ride and it wouldn’t hold idle. I have this same carb on the bike. I turned in the idle screw until it would stay running. It takes 4 to 8 kicks to get started and I’ve been fouling plugs like crazy. I had no idea that there was also an air screw. You’ve saved me a lot of heartache here. Thanks again, awesome video!

Thanks for sharing, always a good thing to have more knowledge about our bikes. Usually when I tune my carb I turn the air screw all the way to the right make the gas richer, make the bike idle in 2-3 rpm and then I turn the air screw slowly to the left make it leaner until the engine idle at its highest rpm it could reach. When the idle rpm is not taking any higher when you turn the air screw counter clockwise thats when I know it's the right setting. Usually it takes 1.5-3 turns to the left to reach, more than that then I'd change the pilot jet size. After I get the air setting then I'll adjust the idle screw.

Used this video and got my 250sx to idle perfect today. So excited! Thanks for the videos Rado. 👍🏻

Best video ive found on this topic. Mine was way off, the bike wouldnt idle and bogged. Idles and rides sweet now!!

Best explanation I've seen. Thank you. Explained and illustrated.

Thank you so much, i was going crazy trying to adjust that screw on a 2 stroke, i was doing it the wrong way !!!!!!. Thanks for taking your time to explain the diference between that screw on a 2 stroke and a 4 stroke.

I really like the way you covered throttle free play!!

I've been riding bikes for years, as well as watching you tube for years and quite honestly this video if by far one of the best I have seen for adjusting pilot jets!!! I wish you all the best with your channel and the great straight to the point here is how its done attitude! Awesome!

6 years later, still helped me out!

Awesome finally someone showing the top screw adjustment.

Had re-jet for warmer weather and used your video to set idle.. thank you I'm running crisp for my Hatfield McCoy riding !!

Thanks man , after watching your video I've fixed my bike , I came home for a short vacation , no time for mechanics , I had to make a temporary insurance and i'm glad that the bike is now running otherwise I would have lost the money of the insurance... anyway thanks again :D you have a new subscriber :D

Best carb tuning vid yet ! Thanks for making it simple to understand

Excellent, I have just bought myself ktm 200 and it's bogging a little in low revs so gonna have a play tomorrow before I take her out. Subscribed

Iv used this a few times now brilliant informative video, thankyou fella my bike is sounding so crisp.

I refer back to this all the time. Simple, effective.

RM 125 with no kick starter( to expensive lol) So jump starting it my driveway a few tiimes then jumping off with the screw driver ,with weird looks by the neibours :):) But eventually got it running sweet :) power valve 1 turn clockwise too wow.. didn't know 125's had bottom-end hahah thankyou mate. Another fan from nth qld Australia.

Thanks a million! this video helped me out a lot, i just bought a KTM Exc 125 if i'm not mistaken it is the same as the one you used on the video, but in any case my idle was too low and always have to pull the choke when i'm not riding or keep my hand on the throttle so this video helped me out a lot i quickly set my screws and now it idles like a dream! thanks DirtnIron keep up the good work!!

Thank you so much for this tip. Big fan of your channel and your work with Jay Clark!

Absolutely the BEST and easiest to follow tutorial on this subject. Super glad you made this video my dude, subbed.

Thanks rado. As usual a very useful and inofrmative video. My beta 250 came with the float level set too high. It was leaking gas from the overflow a lot! Other than that, it seemed to run fine. Once I adjusted the float height lower, the leaking gas went away but now it has a slight bog only when giving it sudden and lots of throttle off idle. Everywhere else, it runs very crisp. I am going to play with the air screw now to see if that fixes it.

This is fantastic! No bullshit. Good video and audio quality. Close up shots. Thank you man

Thank you.. well explained. Now I understand better how it works

Thanks video! Your advice worked perfectly with the general start point on tuning the bike, i kicked it once and it came on idled perfectly! 👍👍👍 Thanks

Thanks for this tutorial. Im going to try it with my Kawasaki Leo Star.

Still thanking you for this tutorial 🙏🏼 🙌🏼

I have my bike jetted perfectly or close to, 158 48 + carb tuned almost perfect. She runs fine. Great video :)

Excellent instructional video!! Thanks man!!

Best tutorial bro. I was doing some research and I know that’s not something very complicated, but u make it so easy to understand ❤️🙏🏻 I got I very nice 2002 ktm 125sx 2 stroke. I be honest that bike is very in mint condition I know I just have to work with this things. The engine only have a fresh 27hr, a tons of new parts. But it bogging in lows rpm like 1/4 throttle before the powerband and torque. I don’t know if is something with the air or fuel. I put v force 3 reed cause I like trails so I just want some smoothest throttle and more power at the acceleration. I know maybe with the v force 3 it don’t gonna run very fast cause it make the bike more like low and mid range, but my bike top speed are just like 47mph. I think I should do a lil tune wt the air-fuel screw to see if it grab a little more power and stop bogging at lows rpm cause the bike have a nice powerband but that little bogging or si leak give me anxietys.

Great video and thank you for the clear explanation. My old DT175 had idle issues and I am at 1/2 turn out to get it to run close to correct. Could not figure out if I needed to go bigger or smaller on the idle jet. Your video explained it well and I used my jet drill set to open it up just a bit and not I'm 2 turns out and it runs perfect!

Thanks for another great video mate, greetings from Australia.

This guy should have more subs

good video really helpful just got my first 2 stroke

Very helpful man people like you are awesome

Crazy clints carb class!!

Best video on the internet thanks brother really helpful info.

Rado Rocks! I need to invite myself out to ride at his place some time. 😂

Thank you man u have the best examples of how to do this I found it very helpful just started riding a 250sx and never had a two stroke always rode 4 stroke I love the ktm just all so new to me and even though it had great throttle response the way the rpms dropped just didn't sound right to me so I played with the throttle screw and air screw out on the trails before I watched this video and I'm glad I watched this later because after all the bike does sound healthy if you're is healthy then mine must be because it does sound the same lol so thank u for the vid

Thx so much!!! I just fixed my moped and it works so great with how you described it! :)

This video was super useful, thanks Bro !

Thank you brother couldn’t figure thing cr85r out thank you

Best video to fix idling 2t bike

I’ve looked everywhere to find a good video on tuning my mikuni carb. Your is the best.

Well that's a great help sir,ive a rd thats not quite right on the left this should help thanks

Perfect video thankyou very much my bike would not idle and this idea perfectly explained which screw in which direction does what and roughly where to set them bike idles perfectly now

Great stuff! Helped me set the idle on my ktm 85.

Works perfectly I was afraid of set the carburator but it's easy

Thank you so much man you fixed my bike

Great advice. Easy to understand and to do. Great tutorial.

Awesome video Rado, and man this 2 stroke sound is killin🤙👌 greetings from Serbia🇷🇸

Awesome video mate! Very straight forward

Thank you so much now my bike is idling perfect

thank you so much for all your educational videos, i have learned so much

Very helpful for this newbie! Thank you.

Thank you for this! I have to borrow my Wife's ear to make sure that it sounds like my 2 stoke. Why I had to borrow my wife's ear? It's because I am deaf. She was telling me about the thumping sounds. So this video cleared it. Sames just the same as yours but needs some slight adjustment for lean or richer.

Exactly what I needed! Love your vids. Greets from the Netherlands

Great information, will be checking the air screw on my old wr250z!

Great video! Thanks for your help!! Stay moto vated!!!!!!

great vid! just what I needed to know

Top Explanation!

Thanks, man. Good explanation. Helped me to understand....

Legend going to use this to adjust the carb on my exc 250 2007 😎👌

As always man, very informative video.

Yes! This was really helpfull! Thnx!

Hey, love the videos. You have very informative videos that are straight to the point. I have an interesting case that I am hoping you can help me with. I recently picked up a 1998 Honda CR250R 2 stroke. I live at 4000ft elevation, and the bike was bought from someone who lived at sea level. The bike runs absolutely great when started, huge amounts of power and immediate throttle response. I would just like to know how to tune the carb per elevation. I did what you did in this video with the 2 turns out, and adjusted the idle, and it seemed to run pretty good, but had trouble starting cold on the next start after. Wondering if its too lean? What I really would love is to figure out a good air/idle screw combo that can run good at my house, but also run good at sea level. Also I am running 32:1 with Motul racing oil. Prior owner was running 44:1 with around a 3/4 turn out on the air screw. From what I have been told though, you should not adjust your fuel/oil ratio...the manufacturer puts it there for a reason. If you are running too rich or too lean, you need to change jets. Any help on this subject would be very much appreciated! This is my first 2T, and god damn its a powerhouse. Just want to really get it restored and running as best it can!

Excelent explained!!! Thank you. Greetings from argentina

Thanks dude, this taught me alot

You are the best man!

Great explanation and demonstration!