davidblythe wrote:when using a bush to step down from 18mm to a 16mm gudgeon pin what do people do re circlips
didnt think about that before i bought the bush

I used to make bushes for the 18 down to 16 to fit the Suzuki piston and lambretta conrod. and I would leave a lip on one end of the bush so the Gudgeon pin was captive inside each bush, then the circlip only had to hold the bush in place. thats how they are usualy made.