Hello Jim
I am curious: have you put many flights on the MS660 since the last postings from May? The reason I want to know is because I have a converted 7.4 Cu.In. (121 cc) Stihl 084 engine that was originally converted by an outfit called "Monster Engines by George" for racing, and than by Ralph Cunnigham to electronic ignition. (attached are pictures of "Before" and "After"). I want to install the engine in a 1/5 scale Hawker Typhoon and found that it is a very tight fit, so, I am relocating the carburetor with a manifold that came off ebay and originally intended for a small motorcycle. This will enable me to put a KS manifold and 90mm Canister.
I hope that this engine will be able to turn a 30-12 propeller at around 5,500 RPM.
I am mostly concerned though about reliability so your comments are most welcome.

Best Regards

Joshua