Thanks for input and for much appreciated instructions.

Have any of you tuned piped the 180?

I notice the rpm say to 12k, surley more is possible. But hearing you the power is found about 8k.

The K&B 1L is the plug to use on the Moki 1.80. Broke in and flew 37 times on the same plug before I sold the engine.

If you are looking for pure speed I would prop for the highest pitch that you can get while keeping the Rpms between 8K and 9K.

Any calcs to give estimate before buying props?

What petrol equivelent is the moki `180?

40cc

thanks.

Ok flew the sundowner today with moki 1.80 swinging 16x12 on staight castor, F plug getting about 8600. Prop sounded nice unloading in air but not overreving. Great vertical and speed. Back flip starts lovely.

Tuned Pipe on the Sundowner with the 16x12, or standard muffler of some kind?

....Ithink Isaw a YouTube vid of this plane, was it yours?

Richard</p>