Actually, I was about to go in and fix the moped and was wondering whether or not it would be okay to just seal the valve shut at all times (or replace the hole that it would leave with a screw)? I heard that the decompression valve isn't really necessary to get a moped started. My moped is a pedal start, I don't know if it matters or not. If not, then I guess I'll take off the head and try to use a spring to hold it closed. Let me know any information when you get the chance.