bore size questions

blaster82

New Member
Jan 27, 2008
401
5
0
hanover PA
ok so i blew up my blaster again with a new top end on it and it only had like 8hrs on the brand new top end but thats besides the point. i rode it for like 2 hrs to break it in and then when i brought it home i put a new air filter and reeds on it and this last friday i went ridin(yeah i know it wasnt broke in enough). but since i put a new filter and reeds in it was runnin just a lil lean but still runnin good. well i was ridin and it just locked up and jammed the rings inside the piston and it may just need a hone job. well my friends dad can do the honing for me but idk the specs for it like the bore size and what the tolerance is as to how much you can go over and under this piston size. what exactly are these sizes and the tolerances on this, oh and by the way mine is already bored .20 over. any answers would be greatly appreciated cause this would be a cheap fix for me this time but idk the specs.
 
.002" clearance is WAY plenty!, I set mine at .0015"
Hone it with 400 grit stones and see if it cleans up, if there are no deep scratches it'll be goo to go.
I don't consider a engine (Blaster) broke in until AT LEAST 2 tanks full of gas has been run thrue it.
And you know the bore size, you just told us it's 66.5mm, .010"=.25mm
 
Piston clearance .002 to .004 inch
Before rebuilding, lets figure out why you are sticking the ring to the piston
Lean mixture from incorrect fuel to air ratio
Maybe a air leak?
 
new air filter so more air is why it was too lean and i already know that i just needed the specs on if i need to bore it or not and i may need to but idk cause i didnt measure it yet
 
any more info on this will be great, just to make sure cause i need tips on this subject cause the person that is doin it isnt a pro at it and idk if i can tell about the clearence and stuff