I have a Satio FA56 with maybe 5 hours on it. I have been out of the hobby for about 4 years so engine hasn't been run. It ran good last time I flew it. I am starting to fly again and been getting my planes ready to go. Yes the Satio was a little gummed up. But I turned it over and has no compression. So I figured it must have a valve stuck open. Pulled the covers and they seem to be moving up and down correctly. They are a little loose, but not stuck. Question is why no compression. I have a Satio 65 set same length of time and I started it yesterday, made a few adjustments and it runs great. Anyone got any ideas?