Hey, thanks for the responses......another related question......I have about 5 different OS engines, ranging from .15 up to a .46AX....

In my old control line days, I always used Cool Power 15% and when I started getting into RC, the hobby shop guy said that 10% would work just fine. Well, it has.....in my budding career, I haven't had any engine problems....If I purchase the OS .52 4 -stroke, will the 10% be a good choice for fuel? Any fuel considerations for breaking the engine in? Thanks again