I have just received a new GP.07 and the instructions call for 15%-20% nitro and I fly all my engines on 10%. Question is, will it run ok with 10%, or do I need to step it up to 15%? I'm not looking for "all out performance", just a reliable engine run. Is there anyone out there that has tried a lower nitro fuel in their .07 engine and how did it do?
Thanks for any help you my have.

You will not be able to get reliable consistant needle setting with 10%. The higher nitro will make the engine much more pleasant to use.

Good luck,

Jim

Smaller engine dissipate heat a lot more readily than larger engine. They simply have more cooling area per displacement. This is why thost little Cox engines really come alive with 25% nitro or even higher.

Your engine will run on 10% no problem, but like w8ye said, it will be much easier to tune and run with a little more nitro. If a reliable run is what you want with the GP 07, a little more nitro will keep the glow plug heated more consistently for better reliable run, especially in the air.

I guess I should have mentioned it before, but I'm going to use it on a sailplane and the throttle will be pinned to run wide open. Do you think this will make any difference?

As long as 10% gives you good power for the climb, then it should work just fine.

Thanks fellows for all your help!
RCU... What a Site!!

I have that engine mounted on a herr
aquastar. It runs good on 10 % and I do not have to readjust the needle valve. The temp here is on the average minus 10 Celcius.
You would get more power with more nitro if more power is needed.

The TT .07 is a very nice engine.

I have a 2 ounce tank on the aquastar with the .07 TT engine.

You might want to use a smaller tank if you are going to use this engine wide open on a sailplane. Wide open this engine lasts approximately 10 minutes with a 2 ounce tank.

I thought my Cox Dragonfly was good just to get a 7 min run! The Gentle Lady will get speck high on that. I guess I'll need about 1 1/2 oz tank. Thanks for the info. 10min on 2oz... I had no idea!