ORIGINAL: Bax
We'd consider a 12 x 6 3-blade prop rather large for your engine. That prop's more suited to be run on a .91-size 4-stroke engine.
With a good-quality fuel, we've not seen any particular problems when the fuel/exhaust system's connected per the instructions. We would, though, recommend a fuel with castor oil in the mix because the engine's non-ringed.
We have no problems honoring the warranty. The difficulty comes when people think the warranty covers ALL problems. It only covers actual defects in parts and workmanship of the original manufacture. Not everything that happens to the engine, whether accidental or not.
Bax, I wasn't speaking from experience about warranty issues as I have never had any problems with any of my engines (they are all OS). I guess reading too much can be a bad thing sometimes. I was reading complaints about the FL-70 engine on this site and I got a little concerned is all.
You say the 12x6 3-blade prop is two big? I was using a suggested 13x6 2-blade which is within the suggested range and went by the recommended -1" from the diameter or pitch for a 3-blade. Maybe a 11x6 3-blade then? This will be my first 3-blade so I am not quite sure about picking a size. I am not looking for high performance, but just a more scale look for my Cessna.
Is the PowerMaster fuel I am using, 15% nitro & 18% castor/synthetic blend; a good quality fuel to use? This is my first 4-stroke and I don't want to ruin it for sure.
I wasn't trying to make accusations, I was just concerned with the things I was reading about the engine including people calling it junk.
Thanks for the help. Gene