I just finished a Sig Hog Bipe with a YS-91-AC engine an OS-F plug, using 20% nitro 20% oil. I have 4 flights on it so far. Engine runs great, lots of power and sounds good too. This is my second 4 stroke engine.

I like to fly SLOW and low, most of my flight time so far has been less than 1/2 throttle. I would like to slow the plane down some without fear of over revving when I do go full throttle.

I am still running a little on the rich side being still new about 8000 rpms. It leaves a nice smoke trail. The prop that I have been using is a Zinger 15X6-10. This is a prop that has a 10 pitch in close to the hub and tappers out to 6 pitch at the tip.

Any tips would be appreciated.

Thank,
Tim