Ok, Here is the deal. 03 Raptor, Supposed to be built,bought from a guy that says the guy he got it from said it was built. He has no Idea what was done, he's not into it.Has lotsa stuff on it,and i'm not familiar with some of it.Has yoshimura full system, shock covers,dynatek modual[Brain ?] with three different advanse curves?[little switches] skid plates all around. and the bars around by your feet. Airbox has clamps onto carbs, but what looks like an alum. block it hooks into. The airbox lid has Two red slides built into the top that can be opened up. they are open, were when I got it. This thing is wicked fast,seems like especially on the lower end,but I never got it into high gear yet,only got a 4 acre field and i'm at the other end before I can max it out. Question; can I tell if it has a piston, say 11:1 by the compression??Haven't a compression tool, but If I could find out that way I'd get one. Any Ideas or educated guesses???Maybe if I had an Idea of different compressions for different size pistons I'd at least have a clue. Oh ya, starts and idles fine, runs very smooth.I've had no trouble starting it in teen weather, but runs better when its warmer. Thanks for your input in advance guys.