OK, after nearly 11 years in this hobby I bought an OS engine, today I recieved a Graupner .30 Wankel that says all over it that it was made by OS. I ran 6 OZ. of fuel through it just to try it out, I'm going to put it on my Sig LT 25, I would like to hear from some others who have flown this engine. Especially I'd like to know how it does with no muffler pressure, there is no provision for it.