Hello to all.
I have a new OS 120 Surpass 3 with about 1/2 gallon of fuel through it. Fuel is 18% Klotz Super Techniplate and 10% nitro and I have OS type F glow plug.
I can get 2200 rpm idle and 8800 rpm full throttle with a Graupner 15-8 prop. Does this rpm are OK or should it get some more? (the transition is excelent)

Thanks in advance.

I have a freind down at the field with one, He runs 20% nitro and run a 16/8 apc prop and run 17/6... you prop seems a little small.

you should pull 8500 - 9000 with a 16/7

Hi.
First thanks for your reply.
I donīt have enough ground clearence for a 16 prop so I use a 15-8. The OS manual says that this is one of the recomended props.

Graupner props load up a lot more that APC, so it sounds OK to me.