I have an 87 250R. the cylinder is bored out .080 over, ported and polished, with a Boyesen Rad Valve, Boyesen Reeds, and LRD adjustable pipe and silencer. I rac MX. My question is what carb should i get, the 38mm PWK or 39 PWK. which would be better, i plan on getting a Pro-X cylinder soon from LRD, but can't decide on the 265, or 300. I don't want to buy the 38 now, then have to shell out more cash for the 39.

Also, what jetting should i run. I will be racing in primarily western PA. Fox, Challenger, Pymatuning, Maple Shade, Mt. Morris, what would be the idle jetting for this area?

 

for mx, def. get the 38 AS..it is a better all-around carb, the 39 PWK would be a better setup for drag racing and duning.