need to know carb size for 82 250r

[90four5spd]

I have a 82 ATC 250r that I am rebuilding. The people I bought the bike from put a huge aftermarket carb on it and i am wanting to go back to stock, mainly because I have to replace the piston (it was fried), and I dont know how to jet the carb for the right air fuel mixture. I need to know one of two things. Does anyone have a proven combo to make the bike run faster (carb size and jet info for correct air fuel mixture), OR does anyone know the size of a stock carb for a 82 atc 250r. I was on ebay and someone had one off of a 84 and they said it was a 31 mm. I just need to know the size or point me into the right direction of where I could find that info. I do have a manual, and it does not tell what size the carb is for the bike. ANY help would be appreciated. Thanks

[kris]

the stock size is 27 mm wich i think is a little small!

maybe try the '84 carb en try the stock mixture of that one.

[trikerooster]

I have a 82' with a 34mm. I tried to go back to stock and it ran like a 185. It was bogging out. I fell in love with the speed and reliability of a 34.

[fabiodriven]

Yeah, 27mm is wayy too small for those engines, although that is what they had on them from the factory. I'd go with the 34mm if I were you.

[Guccimonty805]

I have an 82 atc 250r engine.what is the stock carb size and model number I can't find anyinfo for one

[atc300r]

Stock 81-82 is 27 pe like stated and are to small .I'm running a 38 Mikuni tmx from a 01 cr 250 on my 83 250r.Runs great .

[Dirtcrasher]

I'd think you could jet a 36 or 38mm Mik without an issue. Amazing to know they called for a 27mm...

[Gripit'n'ripit]

did a first gen build. started with the stock and it was SLOOOOOW....but reliable. Moved to a 34mm carb, took maybe 3-4 kicks to start.