I just got a new Husqvarna 550xp and tested the compression and it only came out to 90psi. So I tested the compression on my well broken in 562xp and it reads 105psi. I also have a Chinese Redmax clone that I got for fun and it reads even higher at 115psi. I always thought that 150psi was considered the "A" grade so why are mine so low? And is it normal for these pro grade Husky's to have lower compression?