RE: ys fz110 (not the s version)
I get 8500 on a 16x6 Xoar (about the same load as 15x8) with 30% on a just broken new one. Are you sure you got the cam on the right tooth?
Carb spitting a little fuel is normal. Needs broke in yet to get max power. If the top end RPM falls off then it's too lean.