Beta Riders Club Discussion Forum

What should the compression pressure be for my 2021 500 RR-S? I can’t find any official values. With the auto decompressor, I can’t imagine I’d see near the 160psi I calculated based on the compression ratio and my elevation, but I haven’t done the test yet. I bought a leakdown tester instead, but I’m not sure how long the pressure should hold to pass the test. My end goal is to know whether or not I need to do my top end piston and rings. I’m at 90 hours on the motor.

At 90 hours it's barely broken in. In my experience even the 300 2T piston and rings are fine at 90hr, I've heard of people easily getting twice that many hours out of them.