2006 rmk 600 compression

good compression should be between 120-130psi higher is better but lower you may be looking at a rebuild. Probly close to time for a rebuild anyway with that many miles. Hope this helps.

It is altitude dependent. Not the actual C/R but what a standard compression tester will give you in PSI. So a healthy motor at 300' might read 150 psi then take that measurement again at 10,000' and you might see 108psi. Its still a healthy motor at 10,000', its just the air density is significantly lower at that altitude.

Also, a ported motor may read lower with a compression gauge than a non-ported motor because the cylinder isn't "sealed" as long during the compression stroke, but it will flow more air and make more power.

I had an Indy 500 that read 80 psi cold at 7700', and it was healthy (just broken in from a rebuild actually). Never did check what it read at low altitude though.

Just some food for thought.

if you had 80 psi where i am around 1000' the engine wouldnt even run! you'd be lucky to get it to run at 90 psi. But yes elevation will play a role in compression.