How to Jet a Dirt Bike Carburetor - Jetting and Needles 

This video helped me so much in tuning my carb on my 250sx! Thank you 100 times over and keep up the awesome videos!

EFi was a cool line Best line was the suppressed 300 blackout line 😂😂 Rock on bro. I feel that

“Until we get EFI on these bikes, which we probably won’t” aged like milk, but I’m glad :)

Don't know if I mentioned this in a previous video comment.......I include a strong, small, flat magnet in my butt bag while on the trail. I do this to magnetically capture the needle clip......to change clip position...press against the magnet....it hangs onto clip.....select what position you want the clip in and, again, press the clip with the magnet. I arrived at this idea after losing a clip/looking for it for an hour in the dust and having to jury-rig a tiny piece of wire to act as a clip. Also, I carry an extra clip in my butt bag in a tiny container.

Do you need to mess around with the carb when changing exhausts ?? My cr125 01 keeps loosing spark due to getting covered with oil.

I have a big bore from a 125 to a 134, I have the stock jetting which actually works for where I am. I called multiple places and they said it should be running lean but it seems to be running rich. So my question is can I go with the factory jetting chart, and is my big bore requiring a richer or leaner jet. The main is a 380 which seems massive. Main-380 Needle jet-45 Needle-6beg20-68 3rd from top Air screw-2-1/2

Type of jet for a kdx 200 at 3-5 thousand feet and 70-95 degree weather?

what about reeds? I'm new to bikes...

Mate, how do i know wich jets and needles to use in each situations?

The most I've learned from a video in a long time..great filming, great explanations, and your terminology such as "little white plastic thing" and "this thing, I don't know what it's called" is my kind of language. I now know exactly what to do and how to do it, and I'll definitley be subscribing. Keep up the great work, ride hard, and be safe!!

Damnit why haven't I thought of that spring trick before... I've shot countless springs across the garage trying to get them on lmao

tf is jetting ? damn and i wanted to get a 2 stroke . I don't know shit about mechanic , all i want to do is ride and hope my shit doesn't break , lmao .

i like the way you put the spring back on and the joke about 300 blackout was funny

I love how easy you make that look and you explain it real well! I feel pretty confident my 2 stroke will be fine thanks to you lol

Wow i feel like a dummy that tip with the spring haha the same way it comes off is never fun well ill be doing it your way from now on thanks for the tip

"we'll never get EFI 2T"

I think you should talk about reading Piston Wash/Scavenge Pattern when discussing proper jetting setup. Other than EGT's (Exhaust Gas Temps), a proper wash on your piston is the only real way to know if you've got the bike jetted right, without peppering a piston. Reading numbers in a manual is fine, but it doesnt tell you if thats where your bike should truly be. Proof is in the carbon!

"Now you just twist the spring on . . . " * jaw hits floor* "D'oh, Why have I never thought of that!"

I never wanted to touch the carb just cause I had no idea what to do. That video was great, I will definitely save some money by doing this myself. Cheers. Keep the great vids coming.

What a prediction...3 years ago we didn't have fuel injection

This title should be "How to swap a jet out".

That’s a good carb spring tip....I will try it...thanks

Thanks for making this Kyle; just bought a KTM 300XC, and this helped a lot, especially the trick you used for re-installing the spring!

you could avoid that mess if you used drain screw and hose to drain the floatbowl. its easy to collect all the gas.

What's the difference in doing all this rather than just adjusting your high and low speed?

how do you know what jets to use? I have an 01 yz125 had the engien rebuilt and I rebuilt the carb it has a pro curcit pipe and v force reeds and ik those play into what jets you use just don't know what jets to use so please help lol

tip... try not to ever use the open end side of the wrenches on any bolt. Always use the box end (preferably 6 sided) to break bolts loose and to tighten.

daamn now that theres tpi bikes and lectron carbs man :D

Damn... i feel like an idiot for struggling with those springs for the past 15 years hahah. Never thought about putting it back like that. Great video!

I bought a new 2016 sx 250 . First time I went on it spark plug fouled straight away before I got on track. Anyway to cut it short my air fuel mixture was out by half a turn so I put it back to settings out Manuel which was 2 turns from right the way in n haven't had any problems since

THANK YOU! Saved me taking it to the store and wasting money, was actually enjoy-able learning this for myself.

I have seen lots of great videos on the mechanical aspects of working on the carb, but I wish there was a video that demonstrated symptomatic effects of improper jeting. ie. How the bike runs when to lean or to rich on all 3 components main,pilot and needle.

I watched a dozen videos on carbs and it all sounded like Chinese to me. Watched your video and it all clicked. Thank you, your a natural instructor.

You had me suppressed subsonic lmfao

Neat trick with the slide return spring, I'll be sure to use that if I dont have needle nose pliers on me.

But how did you know which jet and needle/needle position to use? Are there charts or something?

I have a 2003 KTM 125 SX, I need to remove the float bowl in order to change the pilot jet, which is a bummer. It would be nice if I could access both the main and pilot jet from the center hex cap.

When you pulling the needle and throttle cable out of the carburator at 6:50. What is creating that resistance and pushing the needle and lever back inside the carburator? I'm worry to pull the needle up? Even needle and slider are moving easily, I feel like I will pull too much on the spring. Do I have to release or pull anything to get the needle out of carb body?

solved the problem now it was a split in the inlet rubber so when i rapped the throttle on it opened up letting excess air into the mix killing the engine thanks anyway

I have a 2008 ktm 300 xc. I don't ride above 2000ft. I bought the bike used. The guy was running a needle I never seen and has no indications on it on notch 3, 175 main, and 38 pilot, air screw was way out and ran great. All of a sudden the other day I lost a ton of low end power. Rejetted multiple times still had issue. I believe it's the reeds so I'm gunna get vforce 4 reeds. Will I need to rejet for the reeds? Or can I follow the book?

I don’t know anymore I just bought a 150r and it runs like absolutely sh*t no wonder they don’t have warranties waste of money I took it to 2 different dealerships and they said it runs fine the damn bike bogging like crazy I’m going fast and it just bogs and die and the whole time while riding it backfires sounds like a f****** ak47 goin down the road f*** me dude

of course its easy to take out and reinstall a carb and jets....the harder part is knowing what sizes and clip positions to implement in reguards to your specific altitude ,temp, dew points, riding style,.. ratios etc......

Good instructional video what cylinder head is that on your bike? Looks nice wel the whole bike looks nice in that case

KTM is the hardest bike to work on soo tight every other bike I’ve owned everything is easy accesss I don’t know why ktm has to be soo tight fitting even just to change the spark plug too damn tight need a socket and open end wrench smh 🤦🏼‍♂️

Just courious you mention that bigger the number the richier will be but by tour graphic number 5 was on top that means that the needle goes down. If that's the case you restrict the air and the bike will be leaner. What im missing here?.

This video is very very specific to that model of bike. And has more to do with fitting than tuning. Way to mislead everyone.

and the ghetto way is ive seen people put spring onover the cable on ther side so it never gets into the middle of spring like it should and the spring looks all cockeed and makes throttle stiffer...it does work but its not right

my engine runs a little rough, the same bike (300exc *12) of my friend runs very smooth with much less vibrations, he has a jd jetting kit in it but i think its not only the jetting kit. what should i do? needles,... are in standard positions and standard size (right adjustment for my area) - nice video but hard to understand for a german :-P

Thanks! I wondered why there was such a big bolt under the bowl! Saved me 20 mins :)

Demo bike that never gets ridden?? Too clean!

Spring trick was pretty cool. I hate fighting those fuckers!!!!!

Great video. Finally carbs make sense. Thank you!

hi all, how to remove slide stopper from ktm 300 exc 2013 carburetor

Thank you so much!!! you make this stuff so easy!!! been following your channel for awhile now and you have saved me so many headaches!! keep it up bro!!

Nice videos man! I have watched a few and have been impressed. Well done! Subbed.

people with lectron carbs laughing rn lucky pricks :/

Thank you for a good hands on video with ktm 2-stroke jetting in hi-quality video!

You don;t need to take off the chain guard, just wiggle the throttle cable down a bit and the carby will rotate fine.

hi i just put a fmf silencer on my yamaha yz 125 but its spitting oil.. i heard to change the jet.. what jet would you say to put in?

I can't be the only one that can smell this video am I?

Should have drained the carb first

I have that same NAPA socket driver that my dad gave me years ago!

Thanks for the great vid. Very easy to follow.

I can even give you a kiss right now. Thanks a lot.

Oh Boy... i don't know how often i raged out because of this fucking spring. And now you're showing us the simpleest way doing it without any anger. Dude... thank you for showing me how dumb i am for not realizing this.. :D

hi can you tell me why my bike revs fine if i feed the throttle on steady,but off idle if i rap the throttle on it dies,but if i put the choke on half way it is fine,do you think it could be the main jet too lean,it does idle perfect and fuel screw is 1 1/2 turns out with 38 slow jet,my main is a 95 the bike is xr 125 honda

How do you keep dirt out of all the carb when doing this on the trail?

i must say the single most important lesson this vid demonstrates is the spring trick on the slide....that is golden to a newbie and once you do all this and reassemble and bike fires right up...the confidence boost that inspires is priceless and wiill give u more confidence in future tuning sessions. but on the spring method ...until i learned that.. i would feed cable on the bottom of slide and lock it in ONLY AFTER i had put the spring on and as id compress the spring..id hold it in the most compressed position and then use a pair of small vise grips to clamp on the wire right below the spring so it stays in the position it needed to get cable end into groove and seated right..then id pop off the vise grips and slide her in the carb housing... its really frustrating and on average that step took me around 45 mintes of trial and error before i got it locked in correctly and was the single most difficult step for me to complete....so with the spring twist on method....the hole process will go light years faster!!!!

Great Video for a newbie, thanks!

What about the pilot jet? You can't access that without taking the float bowl off. If you're changing mains you probably need to change pilot too.

Hey! I have a 2015 Honda Crf230f and I checked the spark plug and it was VERY white at the tip telling me it is way to lean. I took apart the carb and I have a size 110 main jet and a size 42 pilot jet. Which jets should I buy to get the engine running a proper air/fuel mixture? Thanks!

What does bag jetting sound like?

Lol , 300 BLK OUT is very expensive for a lil yappy mutt like that........ new sub here , keep up the awesome work you're doing ! I'm wanting to get back into dirt bikes and your 4 stroke vs 2 stroke videos have got me thinking now . Had my mind set on a 450 but now I'm thinking 2 stoke.........thanks a lot ! 😂😂😂😂😂😂

Fuck that buy a lectron carby and be done with it

Thanks for your content. I have a 2017 KTM 250 XCW. I was going to follow your instructions to rejet the new Mikuni but access seems really limited. Since you have the new 300 XC, which I assume is similar, any advice on "getting in there?" I have an electronic module hanging down from the frame above the top of the carb.

That little cup at the bottom of spring! Gotta watch that tongue inside of boot. REAL IMPORTANT! Your video with the cup up on the throttle wire FIRST and slide the cup down in SLIDE with the tongue inside of keeper is important. The spring trick was dead on. THANK YOU. Without that trick the cup is a 50/50 of seating correctly. Glad I saw this much earlier. Saved me time and tooling issues. Light at the end of the tunnel was quick.

I’m at 500 feet with a 2006 ktm 125 sx with fmf gold and fmf shorty, trying to figure out the jetting for winter and summer!

Honest question here. Do you really have to change jets mid-way a ride? Cant you just stick pick a mid-way jet and stick with it for the entire ride? I'd understand if something's broken and your bike wont run then it's a good idea to take it apart.

I can make jet needles by hand. hand made needles. i made for my Husky 2 stroke. the metal is phosfor bronze.may be i 'm the only one who can do handmade needles. after assembled the bike moved very good.

with a yz 85 it's a bitch to get the Carb back on

i have a 1995 Suzuki rm250 i think in the bottom bowel in the bottom the air tube i think its called on the inside of the float bowel i think its rubbing on the the float and making it stay open i have gas coming out of every spot when i turn it on have you heard of this and what could be the fix?

i need help its a atv bigbear 400 2007. i have a jet kit put all of it in except the jet. the number of the jet is on top of the jet, but i cant find which one to use i live in east texas.number 138,140,128,124,120,136.thank you

really need help, this new mikuni carb on my 17 300 exc is killing me. I've only done 4.5 hours and opening to mid range gas sounds quite croaky and not smooth, the power isn't all there low down and she's running out of fuel quite quickly. not very good with carbs other than twisting a couple of screws haha, would appreciate some advice.

Man my buddy has a new to him 01 rm 125 thats been bored .50 over, he got it real cheap cause it's sluggish in first, wont even stand up. it pours oil out the pipe like the guy rejetted the carb and put too big of a jet in (which i read below) but would this cause the bike to be sluggish? New power valve? Im dumbfounded. Thanks

Hi, thanks for this great tutorial ! I want to put an FMF Factory Fatty pipe with an FMF Shorty silencer on a '17 KTM sx 125, do you know what jet and what needle i should use please ?

I’m having issues on kx125 with a Athena big bore kit. It hesitates half to three quarter throttle on acceleration then jolts speeds up quick. I cleaned carb but still feels like it’s starving. Do you think the needle should be adjusted?

I have rm 125 and I run 40:1 without a prob and I'm putting a new top end and I would like to drop to 32:1 and keep 32:1 would I mix the gas then jet my carb to 32:1 or is there a way I can pre jet it so whenever I get back together I can just put 32:1 in it and it run good

How do you get the rearmost bolt of the front sprocket/ chain guard "thing" off? I cannot get my hand, or a tool, in there to get the torx bolt off? The rear shock and parts of the engine are in the way..

Hey broski. Quality video. When searching for diy videos there's a lot of garbage, and then there's good ones like yours. Always grateful to the individuals who can pull it off God bless

I get this is a older video but my friends KX 125 has been having trouble with idling and feel like the carb might need new jetting. And I am from Utah and do a lot of higher elevation riding, what would you recommend for the bike?

WTF put in smaller jet but open the needle should have just left it alone here in WV we set and forget jets people say rejet for every 5-7 degrees here you'd be rejeting more than riding we start in the morning at say 45 degrees and by midday it's 80 degrees according to that you'd never make it 5 miles

So why no comments on your wash video, Pressure wash you must love putting greaser back in you swing arm and changing wheel bearings. terrible information terrible wash technique

I think ill just get a efi bike 😅

I thought that dog barking was outside my house. Then I saw your comment and I busted out laughing! Great trick with the spring too! Thanks!

That spring trick is the best thing I have learned in a long time as my arthritic hands get worse. I recently adopted 3 KTMs and this has been a lifesaver on the 300 and the 440. Which brings to mind a question about the 525: Why have modern 4 stroke carbs become so huge and complicated?

Thanks for the great vids.. This one helped me install a JD jet kit on my 2022 ktm 150sx. Test ride tomorrow!!

Very informative. Especially to me, a beginner. It made the carb operating process understandable. Thanks.

Effffff that. No way in he'll I'd ride on the edge of a cliff. Honestly I wouldn't even walk those trails lol.

How to clean 300 carburetor

ive only ridden 4ts and im looking into a 01 yz125, so if im going about 5 miles down the highway to a mx track im good with jetting right? like im not in mountains or anything