TR,

Good report.

The issues you mention are some of the ones I've wondered about.

If the choke plate had a soft rubber face it might seal better. A piece of rubber tube attached to the plate ala OS four stroke choke might work or Todd could machine a groove in a thicker plate or the carb face and install an o-ring. The prop driver, in my opinion should be at least 1/2" larger in diameter. (the OS160FX driver is huge by comparison) If I were to run a wood prop I'd get an aluminum 1-1/4" spinner back plate to put behind it. The power seems to be on par with an average Saito 180 on 10% nitro. Thank goodness it has less vibration than a Saito 180, they have a huge power pulse compared to the OS160FX, which is the smoothest I've run in this class.

Maybe with a larger volume muffler the engine will gain a couple hundred rpm and or loose some db along with the weed wacker sound.