I now have 4 thumpers in my hands to work on.
2 are mine 2 are a friends. All 4 have different pistons. Below is a picture of all 4 pistons, can anyone tell me which version is which?
The bottom left one is a steel one, the shaft and the back end are all steel with a hex key access in the end.
The top left one is the same as the bottom one but all aluminum. With a hex key access in the end.
The bottom right one is all aluminum with a set screw to hold the front on.
The top right one is all aluminum with a screw threw the front to hold the front piece on.
Anyone got a clue?