I have a question about the 800CC engine on my 2012 RZR.


the internet says my compression pressure should be between 165&185. Mine checked out at 130psi on each hole which prompted me to do a leak down test. leak down on both cylinders is between 4&5% which is in the green zone. the gauges I was using only showed around 35-40 psi to get the leak down gauge to zero...I expected it to be around 100psi but if the gauges are made to work together...I guess so.


soooooo WTF? low compression test but perfect leak down? the valves are not adjustable on this motor. do I just say screw what the internet says and trust the leak down results, or should I be worried about the low compression pressure?

 

Did you spray a **** load of nitrous and bend the rods stew? Lol

 

I do some small engine work if you wanna leave it with me for a few days.

 

Ill trade the rzr for your truck for a weekend

 

When you did the leak down test was the piston at the bottom of the cylinder? If you compressed it with air, the air would rotate the piston down unless you had it at TDC. TDC is where a cylinder wears the most, so rotate the engine to TDC and do a leak down test there.

 

engine was at TDC

 

Try another gauge and repeat the compression test... But honestly, if it were mine and still made good power and the two cylinders were real close balance-wise, Id run it.

 

they are about as identical as they can be on both compression and leak down. for those that don't know, my machine spent around 30 minutes 20' deep in the san jac river a little more than a week ago. engine cut before water made it to the cylinder.

 

What gauge you using? I've had gauges vary 5- 45psi diff.

I know your good with your tools just giving ideas to look at

 

not sure what brand. I borrow them from a friend because I don't use them enough to justify buying. probably harbor freight lol.