Jetting the Mikuni TMX Carburetor

[@davidhull4509]

I was sure that I was going to switch to the kehin carb, on my 18 300 xcw. But I tried the jd kit ony mikuni first. I followed the instructions, used the red needle. Follow the jetting recommendations . Also installed the red power valve spring. Wow! Can barely hang on. It flat rips!!! Don't want any more. A beast. It is the fastest 300 I have ever rode. Don't miss my kx 500 any more.

[@highlandcycles]

Awesome!!! I do have a 36mm Kehin on my 300 now and it is pretty amazing. Even more low end.

[@180sxdeano]

I went from Stock (43-73 clip 3, pilot 25, main 440) to JDs (blue needle clip 3, 32.5 pilot, 450 main) what a difference, in Aus so out elevation never gets over 3000ft odd, bit higher else where yet all NAT parks so can't ride them anyway, no oil seeping out of muffler, ran super smooth especially helps on hill climbs and save 1.5L on fuel on the same 50km trail. on a 2018 TE250

[@highlandcycles]

Awesome! It is so good to get them running better!

[@herdfreak2]

I’m learning about jetting for my rebuilt 2001 Suzuki RM 125 stock engine with Pro Circuit full exhaust, using it mostly for hare scrambles here in the Charlotte, NC area.

[@highlandcycles]

James Boreman awesome. I don’t know that much about low elevation

[@natureguppy9642]

your videos are the best, thanks as always

[@highlandcycles]

Glad you like them!

[@scottlichlyter1533]

Here's your shop located have you ever use KLOTZ TWO STROKE OIL, TRY IT.

[@keithbell8960]

Man thanks, I've been struggling with these issues on my 17 husky

[@highlandcycles]

It is a struggle til you get it dialed.

[@igorexas]

i run needle from outlaw rebuild kit for Honda cr250r 04-07 cr250 late models use same carb and works well cost for that kit $ 20-25

[@highlandcycles]

igor semendyayev awesome info

[@rsendurouk3647]

Can u give me a link to that set I'm interested only in needle

[@vladko117]

+send link please

[@igorexas]

@@vladko117 www.pitposse.com/outlaw-racing-carburetor-rebuild-kit.html

[@igorexas]

@@rsendurouk3647 www.pitposse.com/outlaw-racing-carburetor-rebuild-kit.html

[@nomdeguerre13]

watched the whole series, excellent.

[@highlandcycles]

Aoki Gahara thanks so much for watching.

[@rglce25]

Mine was good, it had the one with 3 holes in it on the one side. 03 cr250. I put the JD one in anyways.

[@highlandcycles]

Nice

[@jamesshort5768]

I’ve got the 2017 KTM XC W 125 and put the blue needle in on clip 2.5 and the bike was bogging when opening the throttle quickly and if I didn’t build the revs up high enough between gears it would bog. Ended up with JD jetting recommended jets but using the standard needle and runs perfectly. Might the power valve have something to do with the shape of the needle?

[@highlandcycles]

Maybe

[@davemedsker]

Every time you make a video my '18 TX300 gets more awesome. Thank you so much.Main from factory was 450, now down to 430 and want to lower needle but seat oring is shrunken/ worn out. Factory specs have nothing for needle position 1, can't wait to try it.

[@highlandcycles]

dave medsker stokes to help n

[@MrSTEALTH125]

Are you running this jetting at 40:1 like you mention in some of your other videos? And staying with br7es plug?

[@highlandcycles]

Yes

[@avigaray]

Great video !!!! Thanks a lot for sharing. I have a husqvarna te 300 and had the same problem.

[@highlandcycles]

Thanks for watching

[@henningjung]

Hi... I have been having problems with my KTM exc 300 for some time now. i will get that kit and see how it changes. down here in the Dominican republic

[@highlandcycles]

Henning G.Jung I think it will help a bunch. Let us know

[@henningjung]

highlandcycles hello. So installed my jd kit on friday and toke it for a ride and its was good. Still a lot of oil on the pipe but its runs much better. I think i still need to find that perfect spot...

[@highlandcycles]

Henning G.Jung I would try just a little leaner.

[@farmer3242]

What is your opinion on full synthetic oil vs semi synthetic and oil ratios. My mechanic said full synthetic is better for top end and semi syn is better for bottom end. He runs motul semi syn at 33:1. Iv been running motorex full syn at 50:1. What do you think?

[@highlandcycles]

I don’t think it really matters that much. Synthetic is probably better for high revs and high heat

[@farmer3242]

Would a 19 250xc mikuni carb need this too?

[@highlandcycles]

Yes

[@NinjaBKT]

Jetting the keihin pwk yz 85?

[@jaquecousteau2976]

Great video! I need to jet my 2002 kx 125 just bought the jd jet kit, just put an fmf fatty, fmf shorty and the boysen reed rad valve on the bike, I also live in the east, any suggestions? Now it falls flat on its face after about 3000 rpms at the beginning of the powerband , all jetting is stock now,.

[@highlandcycles]

Huh, might need more gas on top. Bigger main jet?

[@FourthWayRanch]

why are people saying you don't have to fool around with jetting on this carb if you changed the main? did jd stop selling kits for these carbs?

[@highlandcycles]

You always to jet a carb. Now, I don’t have to mess with it once I get it dialed. I ride from 4 to 13K feet without changing jets

[@FourthWayRanch]

@@highlandcycles OK, it just has a much broader range capability for a given jet. I'm gonna try putting these on my 503 rotax skidoo/ultralight engine.

[@FourthWayRanch]

@@highlandcycles do you know of a good EFI kit that would be adaptable to that situation?

[@highlandcycles]

@@FourthWayRanch no

[@gustavob105]

Please, I need help with my mikuni, here in Brazil there are only 300 carburadas, including 2020. Which set up do you recommend? Altitude 600 to 700 meters and temperature 26 degrees celcius ... tank you !!! ✊🏻

[@highlandcycles]

Probably a 410 main, 30 pilot, and the leanest needle you can get. I really like the JD needle but not sure how easy you can get it down there

[@gustavob105]

@@highlandcycles thanks 🙏🏻

[@enmerdeur]

Wow that seems uber lean on the main for a 250. Might have try going leaner on my 300. Thanks for the info.

[@highlandcycles]

Reno 1960 I know it seems lean on paper but the bike and plug don’t lie. It runs perfectly. We have been doing about the same on the 300’s. Some at 390.

[@keithbell8960]

I'm sure you have Lectron and Smart Carb videos?

[@highlandcycles]

Lectron yes, still haven’t tested the smart carb.

[@grutzmac]

Would the jetting be the same for a '18 300 xc? Thanks. Great vid

[@highlandcycles]

Should be

[@Gregg0112]

I see the kit come with the 2 needles and some main jets. Do I use my pilot jets that i have with the bike?

[@highlandcycles]

I would use the pilot that the kit comes with

[@highlandcycles]

Sorry, I forgot to say that the kit comes with a pilot jet too.

[@Gregg0112]

@@highlandcycles Thanks for the reply. Its just on the jd site its says nothing about coming with pilots

[@austinpitts6633]

Just installed jd jet kit on my 22 tc250, still having issues with carb loading up. And a bog/ hesitation around 1/4-1/2 throttle I opened her up again and set float height to spec and made sure everything I installed earlier was in properly. I think jet block gasket seat was not fully compressed as I did first install with carb still I’m bike and was kind of mailing it in (1am) I wish my bike would sound like yours. I hope it does 32.5 pilot needle clip 3rd position and 430 main jet. Elevation is 200’ above sealevel and around 70° and dropping temps

[@highlandcycles]

Good luck. Sounds like you should have it dialed now

[@jamescanaday1542]

I have a 2007 Yamaha YZ 250 F at a 1/8 to 1/4 I have a bad hesitation how do I fix that? Thank you for your videos they are very informative

[@highlandcycles]

You probably need to richen up the pilot circuit. I’d try going up one size on the pilot jet.

[@jamescanaday1542]

highlandcycles Thank you for the information. Do you have videos on how to fix that?

[@highlandcycles]

@@jamescanaday1542 yeah. kzbin.info/www/bejne/gIiVi6hjiN5qh5Y

[@TubolMotoadventures]

regarding hose placement..Earlier we have long river crossing and the water level is around just above the swing arm and later I found out the gear oil is milky.. How did the water get into the engine? The air filter is way above the water level

[@highlandcycles]

Ahhh, that is from the crankcase breather. It is routed down below the engine and in a long crossing the motor will suck water up into it.

[@TubolMotoadventures]

@@highlandcycles so the bike is not for long river crossing or we can just simply re route it above just like the other hose? My 250fx is routed back in the air filter.

[@highlandcycles]

@@TubolMotoadventures Correct. If you are going to do lots of water crossings I would route it up

[@rsendurouk3647]

Great video. I instolle JD block kit and JD jetting kit on to my KTM 300xc 17 for sea level PJ30 blue needle #2.5 MJ 420 but it's way to rich for technical trails... What would u recommend to go for... just trying a PJ 27.5 blue needle #2 MJ 410... Is that the way u would do it or just swap needle for red...

[@nemoterminator5968]

👍

[@F857]

Great vídeo. Do you have a JD jetting kit for KTM 150 sx 2017 with mikuni. TKS.

[@highlandcycles]

Frederico Pinto I don’t have one in stock.

[@F857]

thank you. but can you get it or know where to buy it? what advise?

[@highlandcycles]

@@F857 Yeah, www.jdjetting.com Great folks

[@samozamene1]

I have the jd kit installed, bike runs perfectly and everything, float height set on 8,7mm, the only problem is that the rpm drop drasticly when going downhill to the point when in steep downhill bike dies... any ideas? Gasket is also already replaced, and i have new float valve installed... ty

[@highlandcycles]

Sounds like you have everything right so I’m not sure. Have you replaced the jet block gasket?

[@samozamene1]

@@highlandcycles yes it has been replaced.

[@arloslab3469]

What jetting setup would you roll with on yz125 with mikuni tmx38? any changes

[@arloslab3469]

Just roughly

[@highlandcycles]

What’s in it now and what elevation

[@arloslab3469]

@@highlandcycles My elevation is 574 FT

[@arloslab3469]

@@highlandcycles Im not sure what is in it now but It has that very awkward needle taper.

[@nickschoenly742]

Dude clean your glasses! Lol great video thanks buddy

[@enduro-parts-aus]

If you have set the float height should you not re route your fuel line 🤷🏼‍♂️

[@highlandcycles]

I still do because even with the float height correct, as you bounce and bang through the rocks and whoops it helps keep some of the splash in.

[@enduro-parts-aus]

@@highlandcycles no worries i thought it might over fill the carb bowl if both where done , as im having a strange issue with my mikuni all of a sudden running rich but i think its due to having 200 hours on my piston / rings oops !!

[@loretavillarin3913]

How to used boat ricing mekoni carb.how adjustment

[@highlandcycles]

I am sorry, I don't understand

[@rearwheelslider]

The needle is shaped like that to be lean everywhere except WOT. That shape makes the transition terrible... Thanks EPA/CARB...

[@highlandcycles]

Exactly

[@lbeck119]

Woohoo racing in California 🤘🤘

[@davidbible9110]

do you run Red 2 year-around in all temps?

[@highlandcycles]

David Bible I do. I’m not super picky and it works great.

[@davidbible9110]

@@highlandcycles awsm, just got my jd kit tonite and will be jetting this weekend. Live on the front range and ride between 5k and 10k. thanks again.

[@highlandcycles]

David Bible you're gonna be stoked

[@Carl0sjim3n3z]

Hey bud I have a 21 yz125x and have a jd kit with blue needle in 2nd clip 430 main and 37.5 pilot and still get sppoge. I ride 3 to 4k elevation. What should I drop to on main and pilot? Should I switch to red needle?

[@highlandcycles]

I would run the red needle in #2 leave the main and go to a 35 pilot. Let me know how that goes

[@Carl0sjim3n3z]

@@highlandcycles jd jetting recommends blue needle 3rd clip and 420 main and 40 pilot. I will try both out and see the outcome

[@Carl0sjim3n3z]

What is the difference between red and blue needle?

[@TommyToboggan611]

necj zookner needle

[@specializedbighitfsr]

Question about @7:25 "looping the overflow tube effectively raises the float height".... Does this create any issues with the idle circuit or cause a rich like burbly symptom? Everywhere I read, people talk about the importance of correct float height, and that many of the ktm's came with incorrectly set high float heights from the factory. Not sure if it was my imagination, or my block seal and o ring are going bad, but after doing the overflow tube loop, it seemed as though the bottom end/just off idle up to 1/4 throttle was more burbly/rich feeling. (Got a jd jetting block seal kit on the way just for good measure, forgot to check this out last time I had my carb off) Thanks for your time ;)

[@highlandcycles]

Greg Stritzel great question. You are right about the float height and you do need to adjust that to be correct but once you have that right, looping the tube then helps keep that little bit of splash from going onto the ground when it’s rough on the trail. The jet block gasket should help you quite a bit too.

[@handendaer]

daisy 🤗🏳‍🌈

[@peterkelly807]

Sorry but what did i learn for this video nothing all u do is talk and show nothing waste of time thabk

[@highlandcycles]

I think I shed some light on good jetting for the mikuni carb. It’s not an instructional vide. Here is my instructional one How do you fix the Mikuni TMX 38 Carburetor? kzbin.info/www/bejne/m6WYhGiEhbN4rtU