Originally posted by mrmike
Don't forget ... the OS91 VRDF is most happy with no more than 5% nitro and around 22% oil. Wildcat 5% d/f fuel is the choice of many. If you're not totally familiar with the engine I think it's a good idea to bench run with a Zinger 12x5 and run a couple of tanks of fuel through it then go a tad rich for the first few flights. You might "waste" some fuel bench running to make sure it's close but you'll likely save an airplane: Dead stick landing are a bad thing.
Mike
Not to say also a piston and sleeve....................fuel is a LOT less expensive than a new piston and sleeve................
Jackjet