rebuilding a motor

[kilabeez0]

what is the worst that could happen if you rebuilt your engine and the cam chain snaps? ...because i didn't replace it. it will still be awhile before i complete the project and ride it, but as it is, i never replaced it, and the motor is assembled.

second, how important is grinding the valve seats and valves? when i had my head done by a co-worker who has his own small engine business, he put new valve seals in, but i think that's about it. the valves are recessed into the seats alot, but he said it should be ok as long as i adjust them. so what is the difference if they had been grinded along with the seats?

[TheOlderFox]

Worst case, the chain snaps with a valve open and the piston hits it on the up stroke. The piston can chip or the valve can bend. This is only the case if it is an interference piston, not all are. What machine is there for? Were there notches in the top of the piston or was it flat?

[kilabeez0]

200x, i dont know, i bored it out and put an oversized honda piston in.

[TheOlderFox]

More than likely it is an interference piston (flat on top) I wouldn't be too worried about the chain unless it was adjusted all the way before the rebuild, ie: stretched to its limits. I have yet to snap one.

[83185s]

ive snapped 3 so far on my 185...2 were because the tensioner wasnt totally tight and the other was because i didnt replace it like what happened to yours...i have been lucky to not have anything bad happen except the last one that snapped i was 2 miles or more from the house

[kilabeez0]

o yea i think i remember your story, out in the woods alone