Hydra

What about a countersunk rivett? No heat, no glue. Just a pair of thin metal sheets, one outside, embedded in the concave hole, one inside for fixing the rivett.

Yes. You are right. I will not start any try if I am not absolutely sure. In fact, I have bought a new pistón, but I own several sherpas and, may be, I could test a repair.

Ok. Now I understand your idea, and It sounds fine!

Mmmm. This sounds interesting. But I dont understand "drill and pin" or "drill and screw". I understand the words, but I dont visualize the idea. Could you attach a drawing? Thanks before hand

This central window must be closed because if drilled, the gas goes back to the carburetor. All depend of the transfer diagram. This piston (with central window) would work on a Bultaco pursang, but not on a sherpa

Hi all. I would like to know if is possible to repair this piston. The central window port is a mistake, and I need to close it. How could I save this piston? Welding? Glueing with metal adhesive? Any other idea? Thanks in avance.