I have a Funtana .40 powered by an OS .50 SX, 12x4 prop, aluminum spinner, and Cool Power 15% helicopter fuel. The performance is outstanding and this setup is quite 3D capable. I have noticed, however, that after most flights the spinner is actually quite warm to downright hot. I have used helicopter fuel for years, but I have never had this happen before. I am fairly new to 3D flying, so my initial thought was that I was not using proper throttle management and overspeeding the eingine on downlines. I have tried flying at slower speeds and idling back on downlines, but the spinner is still warm after the flight. Any thoughts?

Thanks,
Bryan

1 get a differnt prop.......lol, not answereing your Q but try a 12.25x3.75.

i think you must be running your engine lean. therefore the engiens hot, then the heat transfers thru the metal of the engine to the spinner.....just a theary

I can see it getting warm if it's an aluminum spinner. Aluminum is a great conductor of heat. You've got a hot engine there and if it's an aluminum backplate connected to an aluminum spinner that engine heat will transfer to the spinner. Now if you've got a plastic spinner I'd be a little concerned. But still if your plastic spinner has an aluminum backplate it will still conduct some heat.

MIke

I had the same prob! Ali backplate, with plastic spinner, even the plastic got hot! My engine was overheating due to low oil content in the fuel.

It's caused by those re-entries back into the atmoshere.

my spinners get hot
but my engines arent over heating
the are aluminum