Main jet Q?

tonywayne

New Member
Feb 21, 2010
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Does a 340 main jet sound to big for fmf pipe, wisco piston, timing advance, vf3 cage and 28mm carb at 2000 feet elev. Any smaller than 340 and it cuts out at WOT or bogs down. Thought maybe somthing might not be right or just eccept it as a good thing that i got that much flow.
 
does seem kinda large. do you know what needle you have in? have you done a leakdown test? if leakdown is good and plug chop looks good i would say run it!!
 
that seems way big. especially since you have a larger carb usually with a larger carb it takes ur main jet down. i would definitely do a leakdown test
 
Ok ill do a leakdown, can you direct me to a good thread for that on here. I plane on taking the jug off anyway to do a diy port job and 3mm crank. thanks for your help