I'm rebuilding the top end of a 1974 TX500A. I'm ready to install the cylinder assembly and the head. The diagrams and shop manual show two o-rings on each cylinder stud. These o-rings appear to go on the top surface of the crankcase, below the paper gasket at the base of the cylinder assembly.

There doesn't seem to be enough room for these o-rings. I'm afraid if I put them in and squish them, I will just tear the paper gasket. I notice that the 1976 XS500 doesn't show them at all on the parts diagram.

I think one o-ring will fit on each stud. I got Yamaha OEM o-rings, so I think I have the right part.

Any ideas?

I found the answer. The o-rings go on top of the base gasket. The photographs in the workshop manual show the o-rings on top of the gasket as the cylinder is installed. The exploded diagrams are not correct.