Piston circlip installation tool.

Installing the circlips in pistons is one big PITA so I am very happy that I figured this one out.

A length of half-inch copper water pipe with slots cut lengthwise at one end to reduce the diameter.
File the circumference so that it will enter into the hole in the piston and a screw clip to close the slots
Next I made a plunger from a piece of steel tubing (wood would be easier...) filed and sanded to fit the interior of the copper piece.

Push the circlip into the copper tube at a 90 degree angle to how it will fit into the piston. Push it in far enough that you can turn it back 90 degrees without it popping out.

Next insert the plunger in the rear of the copper tube, push the circlip to the very lip of the copper tube so that it is ready to slip into the piston. To do this it is necessary to place the copper tube front end down on a hard surface, with a good deal of pressure, while pushing the plunger down.

When the circlip is properly placed place the tool vis-a-vis the piston's wrist pin hole, press it into the hole as tightly as possible and press the plunger again to pop the circlip into the piston.

It may not work the first time, but after a couple of tries it will be in there. You will have to nudge it into the groove using the plunger or a small screw driver.

(I may make a video at some time...)