Bill,
Right, if the cyl/pis were shot, that would certainly be something that could change, but what I mean is something that would "change" that would now require me to use a pump or regulator... That's why at this point I'm trying to stay away from seeking that avenue. I also don't think there is anything wrong with the liner or piston cause it still has plenty of compression and more importantly will hold the compression. I've replaced the tank with a different one, and strapped the old one to the side of the plane right behind the engine... When I get home tonight I'm gonna run some tests with them and see if either the new tank runs it regardless of being in the same position as the old tank, or if the old tank now works since it has been moved up close to the engine. If the problem persists with both I'm going to look closer at the engine.