250-500cc keihn swap for my cr250

Looking at options for a keihn carb on my 01 cr as with all the poor reports of mikunis i seem better off just grabbing a keihn.

What size works best, finding 36-39mm on ebay for very good prices brand new. 199 seems like a steal. I put a lectron on the 125 and love it but spending twice as much as a keihn for the 250 as well seems a bit tough to make happen right now.

Any feedback is appreciated. Looking forward to seeing the 100% true potential of this cr. The suspension was amazing Compared to any husky ive ridden. Really impressed me soaked up big hits with ease which is not typical for them in my experiences. Must have different valving and settings from stock.

Its working so well on the 125 im afraid to disrupt it haha

You should be able to get a good deal on a moded K carb because of all the people that are taking them off to install Lectrons.

The 38mm Airstriker is the one most people switched to. FYI I put the Mikuni TMX back on my bike and it runs great.

I would highly recommend the 38mm Airstriker from JD Jetting (which is also available through Motosportz). He charges $250 total for a new carburetor and his jet kit.

That's what I put on mine after messing with the TMX for months. It smoothed out the hit and gave it a lot more power.

I saw that for sure was considering it. That is probably the way i should go. Always had good luck with jd jetting in my four strokes. Never used it for a 2 stroke but am sure will be just as pleased.

Ive played with keihens and find I like the mikuni
I really like the RB designs modified one too - ive never felt the 125 have so much bottom
end and I like the hit it has
also returned excellent fuel economy
Nothing wrong with old mikuni IMO

whats the difference between a Mikuni TM and a TMX

Im not positive on the differences of mikunis i believe there is even a tmxx !

Well i swapped the 38mm lectron from the 125 onto the 250.

Started first kick with the choke, turned the choke off adjusted the idle, idled perfect, accepted throttle with no hesitation,

Let it warm up, snapped it open a couple times see how it responded on the stand seemed pretty darn good, took it around the block and to a field nearby. Huge improvement, smoother, smoother and huge gain in top end. All without changing anything from the 125 settings. Unreal to me,


Side note, what is the stock gearing on these? I.looked at my sprockets and i have 15-50 gearing, feels like highway gearing to me. Im hoping stock was 13-50 and i can throw a 13 front sprocket and get a better feel for it.

Hey thanks i did a bunch more searching and that is also what i found. Hard to dig up specs sometimes!

15-50 is a big jump from 13-48 that will be a huge difference going to a 13 tooth. Pretty excited honestly as that is alot of snappiness and acceleration to be gained. I was going to be disappointed if it was close to stock specs and it was just this mellow overall if that makes sense.