[bfd]

I've got some pistons that are supposed to use the normal 15mm size pin but the hole measures about 14.9mm. Is this a machine shop type of job? All the adjustable reamers here at work are much too big. Is it silly to think a dremel sanding drum can expand this hole properly?
bfd

 

[jbranson]

Bill,
That's very unusual for it to be off like that. So you are talking the wrist pin hole is about .004" undersize? An OEM piston?

That's a very very critical fit...typically done with a dedicated Sunnen wrist pin hone.

They aren't press fit pins are they? Never seen that on a bike...doesn't mean it's not possible.

Pete Talabach might be able to give you some idea of your options.
JohnnyB

 

[bfd]

JohnnyB
These aren't OEM but a good Ebay deal that is ending up pretty pricey. The supplied rings were 2mm o.s. and had to be replaced too. The pin diameter is correct so the problem is the piston. I'll try Pete or FrankC
bfd

 

[xander450]

Who sold you the pistons? For what bike? Let us know so we can avoid!

A

 

[bfd]

These are Kening brand for a Superhawk. I can't say to avoid them as I still intend to use them. I think a machine shop can fix them easily.
bfd