I've used both the OS #8 and the F successfully. I run the F now. They last forever.

The first year I ran the 1.60, I had a problem with blowing the seals out of the plugs. Finally traced it to doing warm starts of the engine using a starter. Now I simply backflip the engine using the spinner. Starts easier than with a starter, and zero blown selas since. My engine ALWAYS starts on the first or second backflip. I've had 3 of them, all act the same way.

Jon Lowe