Can anyone tell me what the compression should be around on my 01 CR250 motor. I got about 120psi, and I was told it needs to be above 170psi. I've got my piston rings on me, and I'm 1 radiator hose away from pulling the cylinder up and off, but I'm not going to yet if that's rediculous. Reading around on the net I found 120 to be just right. Anyone know better?

I think that you were told right.  From what I can find stock compression should be around 180 psi, so you might have piston rings a leakin.

Pull the plug and add a liquid ounce or so of oil to the cylinder then check your compression. If it comes up your rings are leaking. If you continue to lose pressure and get a low reading you have a valve issue. Hope that helps to diagnose the trouble. 120psi sounds a little low to me.

^

thats right, forgot to add that.

Joined the thread late but i just tested my 01 cr250r its stock besides vforce3 reeds and fmf gnarly. I bought it from a guy on craigslist for 1200$ he was scared of it said he only rode 3 times. it runs great but i wanted tl make sure the motor was good before i got on the pipe to much. 10 kicks and it read 170-173psi. I read im multiple forums that 180psi is what a fresh stock motor should have so i was pleased. Though compression test on a 2stroke isnt necessarily the most accurate way to test engine wear. But between compression and leakdown i have a very good idea. 

how did you host pic?, btw welcome to forums
anyways replace the first [img]http://tag with this [img width=800] will make your image appear smaller but will have full resolution appear with a click. ( it alleviates scrolling
Aaron

We should post a sign that says 10 yr old threads welcome.
Cool.
Buddha.

Unlike me reviving zombie threads for the sake of it lol, this one imho has some importance still.
Aaron