So I think I have an air leak and I'm almost sure the decompression valve is part of the problem. I've taken the exhaust off, and when I turn the variator, I can hear air escaping somewhere. When I put my finger in the exhaust hole, and cover the little hole that leads to the decomp valve, I can feel the compression increase, and air trying to escape around my finger, even when I'm not pushing the valve down.
Is this supposed to happen? I'm assuming everything should be airtight. How hard should it be to move the piston without pushing the decomp valve down?