93 XR250L Mikuni 32 or 34 mm carb

Hello I asked this question in the XR250 forum and someone suggested that I post it here.

I'm going to rebuild the engine on my 93 XR250L this winter and would like some help picking out the right size carb. I'm planing on installing a 77mm piston, with a mild porting of the head, swap the L cam for the R cam. with new valve springs. Already installed a 99 up XR250R header (ground the welds) with a FMF Q2 muffler and opened up the air box. Looking at the Mikuni flatslide carbs thinking the 32mm but not sure if I should bump it up to the 34mm. Bike is used 90% street 10% off-road. Any suggestions you can give me will be greatly appreciated. Thanks Jonny

Hey Johnny.

since no one else has chimed in i will say something. lots of people want a bigger carb. they think well i bored it over, i got a cam and ported and polished. but your stock carb will work with correct jets. ask redrider1314. he knows more about the stock.

i however went the same route you did. i have the 34mm flat slide with 1/4 turn race throttle. its a beast!! does stumble a bit in the low rpms. but it screams all the way to redline. i want to bring mine in to have it dyno to see if i am running lean or rich during any rpm range. but some people think that carb doesnt work well at all. they say get a pumper carb and it will be faster. i dunno. its really up to you. if yours is mainly street you may want to keep your stock and mod it out and jet right. i ride alot of the street with mine and its alright seems much faster than stock.

dont know if that helps but the one part i like best about having my 34mm is showing people the sticker that says "Not For Aircraft Use" hehehhahah i think that is just bada**.

dont know if that helps but the one part i like best... is showing people the sticker that says "Not For Aircraft Use" hehehhahah i think that is just bada**.

Funny man. :excuseme:

I work on Boeing all day...

Technically, any part that doesn't have an FAA-PMA stamp or an 8130-2 certificate is "not for aircraft use." Even my blue painters tape has to have a sticker that says "Not For Aircraft Use." -BIG DAN:thumbsup:

id go 32mm.

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