fainjon

I had an os25fx and was running 15%nitro 15%castor and when i would break down the engine it looked like the day i bought it. I recently took apart my irvine 53 and i found carbon in the head and on the piston. i was running 15%nitro and 18%castor with the irvine, the irvine has a longer stroke which means higher compression. If i go to say 5% nitro will it run cool enough to keep the castor oil from burning. It was running rich and 15% is at the high end of the recomended nitro for these engines. I would also like to keep using castor oil in my fuel.

MerlinL14

Irvines run better on 5%, they are UK engines and as nitro is expensive here they are timed to run on 5%.