Ken, I had to send one back about 3 years ago, it was one of the very last .50s Saito made. It had soft compression, I pulled the cylinder off of the base and could see a small black speck near the intake valve, thinking it was something holding the intake valve open I tried to dislodge it. It turned out to be a very small casting flaw in the head casting and compression was leaking around the valve seat. I sent it to Horizon on Thursday and had it back Tuesday with a new cylinder. Fastest turn around ever.