Dave,

I have followed your many posts on getting the YS 45 dialed in. All I can say is WOW! I richened it up just a little because I am afraid I am going to blow it up. This thing is running like a bat. (No, I am not complaining [sm=biggrin.gif] )

But seriously, I really inspected this engine before mounting it to my ultrastick to make sure that things like the rear bearing were ok, and the pump was in good order (I got this used from a guy who didn't know how to tune it).

What is the realistic SAFE RPM range for this engine. I am running the APC 12.25 X 3.75 on it as you mentioned in an earlier post. Going up, it is phenomenal compared to the Webra I had before. On a short field take off, I actually accelerate in the vertical. But I am petrified of downhill run with anything more than about 1/3 throttle because it is spinning up so fast. One other thing that an old timer told me not to worry about, there appears to be fuel lightly spraying from the front bearing while static testing at higher RPMs. It that OK?

FWIW 15% cool power Synthetic, OS #8, One head shim. Needle set to throw a healthy smoke trail when motoring around the sky, and a rich enough at idle to load up if setting on the stand too long.

Bob

P.S. I am in the process of rebuilding the one that shredded the bearing for my New KAOS.