Today I fired up a New OS 46fx to run a tank of fuel thru it before its maiden flight next weekend.
This thing was VERY sluggish on throttle up, and never seemed to reach max RMP.

Am I doing something wrong?

Does OS not like 10% nitro? (all I have at the moment)

Does low end screw need to be leaned out a little?

I am begining to think I should have got another Tunder Tiger......
cause this isnt right from what I remember of OS in the past.