Big Bore

[Boggs#3]

Ok the rod whent out of my r the other day so i decided to put a big bore on it while i have it apart. I got it of my cousin for free it was on my bike when he owned it he put it on there when he fist got it to get it running. The size is 72.95 mm does any body know what size it is or where to get the next one up? Also at the bottom off both piston skirts there is like dents in it and a small crack? Also i have a stock shaved head what would i have to do to get this to work? Thanks for your help.

[Brett250R]

310, solid engine

-Brett-

[parttime]

is it a prox cylinder? if so a 73.5 would be the next size up.

[Boggs#3]

I dont know if it is a pro x one or not. Thanks

[TheFontMaster]

If the piston has any cracks you need to get a new one. Don't even think about running it in your motor.

[C-LEIGH RACING]

Piston cracks come from to much piston to cylinder bore clearance & can come for just running them to long, either way its a clearance issue & the piston skirt slapping around.
Neil