I have my topend off now because of a loud ticking noise. It goes away when you give it a little throttle but pretty loud at idle. Dealer says rod knock but others say piston slap. Ritter says piston cause polaris rods come apart pretty quick. Piston is about two years old and had a small tick at install. Is there a way to tell rod knock other than the rubber hammer trick. It sounds pretty solid by tapping on top of the rod. The piston has blow by and the cylinder walls look shiny in some places and not in others. It looks as if the rings are not touching the sides in some places. Piston has marks running up and down on it but it looks pretty decent for a two year old. What sould the clearance be for a new piston cause it is getting a new one since it is apart. No porting on cylinder.

 

A certain amount of "rattle" at idle can be considered a "normal" condition. To measure your piston: take measurements 1/2" down from the top at 90 to each other. Repeat 1/2" up from the bottom.
To inspect the rod: use a magnifying glass to check the bearing and inpect the bore of the rod. With the bearing an piston pin installed twist ends back and forth to check for excessive axial or radial play. Piston clearance is .0023-.0037. There are some variances people run with this. As long as you have it all apart, I would bore it out, get a Wiseco piston, new rod end bearing, and consider it fresh.

Ken

 

Ditto. I try to make it a habit of changing top ends every 12-18 months just to be safe. Check your compression regulary as well once the new one is broken in.