Compression

[SwampRatt]

Just checked the compression on an 09 mxz 800 with only 1050 miles, I get 95 and 100 psi on each side. I'm curious as to why both are equally so low, and it's not my gauge as I tested 2 other sleds sitting here which both read 130+. Input anyone? Or just start the rebuild and don't question it. Thanks all

 

[iceman5689]

140 PSI from factory. I'd put a new top end kit in anything under 100 PSI. Pistons are definitely passing and cylinders possibly scored at that pressure. Hope you don't have to replace youre jugs, this can get costly. With this year you might want to look into bottom end also.