Intalled 1mm over high compression pistion. 250sx question

[andersonee4]

The head gasket opening for the piston was slightly smaller than the bore. is this supposed to be trimmed and if so how? also i noticed that the base to jug gasket protruded into the chain area. Are these issues something to worry about. The piston doesn't come high enough to hit the gasket when top dead center so whats the deal?

[WilliamJ]

If the fire ring is exposed it will likely overheat, cause detonation and get burnt away. You must get a gasket which does not overhang - you can’t usually trim them. The gasket at the bottom of the jug will be fine as long as there is clearance to the chain.

[Dirtcrasher]

The deal is that it's in the combustion chamber and if built like most head gaskets, it has a crease at it's innermost position which you can't dremel away such as you could with a solid copper head gasket. You will have detonation and the pieces that burn/break up will cause issues; 1MM is a good sized area.

The base gasket, you could have trimmed but it won't cause an issue anyhow; It's not in the combustion chamber..........

[andersonee4]

damn, i put it all together today, and cant remember how it looked. after i put the dowels in the jug through the gaskets, it seemed to straighten itself out, but i cant remember. Guess it's coming apart this weekend.