I had the same problems with my Saito 180 on my GP super stearman. Do the following:

- Place this engine in simpler airframes like Extras and forget stearman.
- Use dubro anti-vibrating aluminum mount.
- Forget 16x8 props. Use props equal or greater than 17x8 APC to lower rpms.
- Change the stock muffler (that is like bell) with the alternative Saito offers that is like cylinder and the inlet is centered to the top. Use teflon tape to lock the thread. It was the only way for me to solve the muffler coming-loose problem.
- Change rear ball bearing as it is of low quality from the factory and has big tolerance that allows the crankshaft to vibrate a lot. My engine was almost destroyed because of this and I mean the rod hitting the crankcase!
- Never operate the engine at WOT continously. Alway allow small brakes for cooling. Otherwise it will burn the silicone tubing at the muffler and deadstick. It can even destroy the preassure nipple at the muffler.
- Never lean HS needle too much because you will destroy everything.

After lots of trials and efforts to conclude to the above listed, I am now enjoying this powerfull engine but I always keep in mind the limitations.

Stelios