Ok. So I've got about a year and a half on my motor. I had the intake and all off it earlier this month and was checking out the bore by looking through the intake/exhaust. It still all look good, there was still faint cross hatching in the cylinder.
BUT

I stuck my finger through and grabbed the piston skirt and I can rock the base ofte piston back and forth. The compression check gave me 185-187 psi 3 times in a row so I am going to assume that the rings and bore are all still good (pre-break in was 150-160 psi).

The piston, wiseco, still has the grooves all around it, doesn't look worn or anything, so I'm ASSUMING it's still good. After the compression check I'm pretty positive all the 'sealing bits' of it are fine.

But that wiggle I got with the piston,,, are the 250's bad about the pistons collapsing like the 500's? I couldn't tell you how many actual hours I have on the motor because I for really keep up with them.
But yea, I'm positive that rock wasn't there when I rebuilt it.

Am I just being paranoid? Cause it's the original cylinder the bike was raced with and it's on the final bore so I REALLY don't want to trash it. Should I go ahead and start getting everything together to replace the piston?

Thanks y'all!

If it were me I'd rather be safe then sorry a piston costs less then a piston, rod, crank, cylinder, head and whatever else you could damage by letting it go and having it fail.

You need to get it measured. Your probably seeing  @.006" if you feel that much movement. Or the. Cylinder is tapered. Was it bored before the last piston went in.

Yea the cylinder had to get a fresh bore when we rebuilt it. Had a loooooot of slack in the bore then. Fresh bore (to final bore now) and fresh piston

The only part of my cylinder that didn't clean up was the exhaust port bridge. But it was smooth, and perfectly round.