The mainspring: I do not know exactly so can only suggest you try it for fit and see. Check the spring fits inside the piston with a not tight fit. If you have to push it into the piston it is too tight. A bit of a loose fit is OK but you must check that the spring guide also fits the spring .. again you should not have to force it; too tight is not good. You can get away with a slightly loose fit but may get a boing .. but this can be reduced by using a piston liner ... maybe home made from a beer can.
Regarding the piston head. I do not know as I have not done one. Does the rivet go all the way through the head i.e. can you see the pin from both sides? I am getting the impression that the pin has a domed head. If it is domed both sides you could try filing off one dome and then using a punch to drive the rivet out. It must be there to stop the piston head screw from coming loose so must be removed before the screw will undo to release the washer. If you can drift it out, you could put it back but if the head screw can be tightened well then you should be OK without it ... just check that the pin does nothing else other than pass through the head. I do not think it does. Of course, if you put it back, the hole in the screw must line up with the pin.
Cheers, Phil
Originally Posted by Phil Russell
The mainspring: I do not know exactly so can only suggest you try it for fit and see. Check the spring fits inside the piston with a not tight fit. If you have to push it into the piston it is too tight. A bit of a loose fit is OK but you must check that the spring guide also fits the spring .. again you should not have to force it; too tight is not good. You can get away with a slightly loose fit but may get a boing .. but this can be reduced by using a piston liner ... maybe home made from a beer can.
Reply With Quote