Does this wrist pin need replacing?
 

Here is the pic. I have 4 wrist pins that look like this. Should I replace them and if so do they need to be matched to the pistons?
http://forums.pelicanparts.com/uploa...1066666847.jpg

That's just grime from where the oil got splashed up between the piston and rod from underneath. It can be cleaned off. It's pretty rare to see a wrist pin that needs replacing, unless there is other major damage to the rod, etc.

Oil stains are common. Just make sure the pin surface is smooth and that your fingernail doesn't catch on anything when dragged down the pin.

The only bad wrist pins I've ever seen have come from boxes of piston/cylinder sets that have sat on shelves and corroded out from poor storage and disuse.

Thanks guys!

A good rule of thumb is that if your fingernail catches on it (like a groove), then there's reason to worry. If your fingernail doesn't catch, you're okay.

When I used to work in the machine shop, I learn that your eye is good at distinguishing about a 10,000th of an inch, and your fingernail is a little better...

-Wayne

One of the things I always do Wayne...ring the crank.
It puts my mind (what little is left..LOL) at ease to know the crank is sound.
Bob

check out your rocker shafts if you want to see wear. there's usually a few that don't look too good.