I have a RCV 91CD engine with the following problem.

This engine almost always starts at first kick, idles at 2,300 with 14x6 Master Airscrew prop and Omega 15%.

Throttle advance from idle to 3/4 throttle is smooth and rpm reaches 8,900 at this point. But from 3/4 throttle
to full throttle, the engine splutters and rpm drops to 5,500 and remains there. The high end needle is
set up 1 1/2 open. Closing it by 1/4 will not get the rpm up. Neither does opening it by 1 to 2 turns.

I notice 8,900 rpm is the RCV specifications for this engine and prop combination.


Chris