first gasser
 

i picked up a motor out of a smaller chainsaw, i dont know how big it is,(prolly around 21-29cc). it has needle bearings on the con rod, two rings on the piston, some evidence of blow by(just a bit) but my real question is the intake port is on an angle, and i would like to smooth the passage. will cutting the carb BELOW the butterfly ruin the carb? maybe about 1/8 inch in some places. the exhaust port is next, it is only two holes the size of a pencil so i know that could be improved. it is a zama carb and apparently there is a passage from the diaphram chamber up to a port that leads out of the carb.... is this normal?

RE: first gasser
 

Needle bearings are BAD if they are on the crank shaft too ( some of the cheaper saws). They wont take side thrust. You want Ball bearings on the crank. Needles on the con rod are OK

RE: first gasser
 

they wont be getting any side thrust. so am i in the clear to cut beneath the butterfly??

RE: first gasser
 

Cutting the carb after the butterfly and after the ventui is OK.
But a bigger carb is easier.

RE: first gasser
 

yeah, but i dont think i will find a carb to fit the block without a real mod job, im just looking to smooth anyway. the bore is .725 inches, so i hope its big enough. tx for the info...

RE: first gasser
 

Before you fix something that broke, convert the engine and get it running correctly. Then play with things, that way you will know if the idea was a good one.