Originally Posted by
aspeed
I normally use 50-50 castor synth. but don't really see why this motor would need it, being true ABC and Ball Bearings. Maybe because of the bushed rod material? or just to be on the safe side I guess.
It would be of importance for the unbushed conrod in the .09 that was changed by adding in the .15. If one were to bore out the hole and press in a bronze or brass bushing in each conrod end, then may be able to use standard RC fuel with the .09. Of course, Castor such as your 50-50% mix with 20% total oil would provide protection against a lean run, certainly can't hurt. Instructions mentions Castor drawing heat away through the exhaust helping engine to run cooler. Given the restrictive muffler would cause the engine to run hotter than a free flowing one. Instructions also contain a warning of not running the engine in an overly lean condition, should be set slightly rich.