I have an O.S. .25 SF that I purchased quite a while back and am looking to get a new piston sleeve (reason below). Clearly they don't manufacture the engine but, I'd like to find out if there is a comparable .25 that's built today that I can purchase parts from. If so, what engine? I'd really like to keep this engine going as it was my first r/c engine, and thus means a lot to me.
Here's a link to another thread with pix of my OS .25.
The Reason: I'm loosing power in-flight as the engine runs longer and I'm fairly certain the compression is becoming less and less as the engine heats up. I don't have any issues during idle (approx. 2500RPM on idle) but the longer it runs it starts to loose power. It's an open faced cowling (E-flite Texan conversion to glow) so getting air through the cooling fins doesn't seem to be an issue.
Either way, I'd like to know if there is an existing engine out there I can swap parts with. Thank you.