I blend my own using 20% morgans 100% synth. oil, methanol, and nitro from 20-65%. Castor does burn differently and tends to build up on the exhaust valve and can cause issues if the motor sits for awhile. Since switching to the synth. oil my engines have become a lot easier to tune and have had a lot less problems.

Most people seem to be very happy with the results from a 30% nitro/20% oil blend on the 110 to 170 size motors. For sport flying I mostly use 20% since it keeps the cost down. For racing I run in the higher range on my 110's and 120's.

Jimmy Skids