i have an 04 pro-x2 600 what should the compression be? i put a tester on it and at idle it was about 100-110 psi, and when i gave it a little it went to 120 psi.

???????????????????????!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! you don't check compression at idle. You pull all your plugs, hold the throttle wide open and give it a few pulls. All cylinders should read within about 10% of eachother. I would say really good compression should be 130-140. under 120 and it's time to replace some parts.

Should not check with motor running, btw how did you do that, running on 1 cylinder? Warm up, then pull plugs, check each cylinder. s/b within 10% of each other and over 120. I find checking a cold motor gives you a false reading cuz everything is tighter when its cold = higher compression than you actually have.

I was wondering the same thing???

There is always some debate on how to check compression.

Most things are checked at a standard temp, 68F, and standard atmospheric pressure, 29.92 in mercury or 14.696 psi.

By warming the engine and pipe the air is heated and gives you a lower reading, which is actually false.

A cold engine at room temp is usually the best way to go. You may have heated the engine differentlly from the last time you did it giving a different reading.

IMO.

Al

it started right up

ok so i just did it the way you guys said and on the side that looks like it was just replaced before i bought it . you can still see the hone marks on it, only got to about 105-110psi and the side that is bad because you can see the scratces in the cylinder walls got to about 95psi

time for a rebuild.

that sucks because i swear the one side is brand new, oh well i was planning one rebuilding the other side the has the scratches on the walls

should a sled with 2500 miles on it still have good compression?

mines got i think a little over 3000 or maybe just under

Yes. You shouldn't lose much/if any compression until 5,000 miles at least.

pushing 7000 miles on my 700, and still has 130 on both cylinders and all stock. I may freshen it up this year. and 2000 on my 800 with 148 on both cylinders. sucks TO PULL OVER! Runs great after you do.

thanks guys