Lining up the little end bolts with the slot in the gudgeon pin is a really fiddly job due to lack of space for your fingers within the piston.

This is a handy little gadget, simply made.

You will need seven inches of 7/16″ diameter bright steel bar, cut 1 inch off the end and drill a hole in the end of each rod to take a piece of threaded bar, which you will also need to make/or acquire.

File two flats in the long bar to grip in the vice.

Loctite the threaded bar into the six inch piece, and drill for a 3/16″ diameter tee bar in the short piece.

I have made two because I have found two different hole sizes in the gudgeon pins depending on the maker.

Trial fit the pins in the rods first, then heat the piston up in boiling water or with a hot air gun which ever method you prefer. Slide the conrod and hot piston onto the bar, assemble the gudgeon pin slot facing outwards and clamp tight with the tee bar. Assemble with some oil, slide/oscillate the piston and the conrod onto the gudgeon pin, line up and fit the little end bolt/tab washer.

I had this tool in the Grey mag fifteen or so years ago, someone wrote in to say they could do the same job with two bolts pushed into the holes in the gudgeon pin and clamped in the vice, well I suppose you could do it that way, but I prefer my idea – I think it’s far more civilised and much easier to use, and furthermore less likely to cause any damage to that very expensive set of pistons.

Download this article here