I got 10,000 rpm with a 6x4 prop. I was sort of expecting more rpm, but I'm not really sure. Perhaps a smaller prop would be better.
One thing that I thought was interesting was that the engine would run with the needle valve closed all of the way. Upon inspection, it appeared that the spring the tensions the needle valve gets smaller in diameter and wedges itself between the top of the opening and the bottom of the needle valve shoulder to maybe keep the engine from being run too lean. This one was a new one to me.


Wren