912 UL Stumbles at full power.
in General Tech Discussion
4 months ago
My Rotax 912 UL 1535 hrs runs fine for the first minute, then drops from 5200 to 4000 and oscillates between 4000 and 4500. Mag drop is fine, fuel flow has been checked and verified, new fuel filter, new fuel pump.
I even ran a fuel line direct from fuel tank to engine fuel pump. Carburetors have been rebuilt, floats checked, and fuel sockets inspected.
Hydraulic lifters have been checked along with valve train, springs and rocker arms.
The muffler was found to contain loose parts of flame tube which were removed before reinstalling exhaust system.
Engine was tested for crank case fretting with negative results.
has anyone else experienced this issue?
