Hi,

My Fuji 50SB in my GP Christen Eagle II has had about 2 gallons of premium unleaded at 40:1 through it. It's turning an APC 20x8 prop.

Sometimes, especially after several minutes of flying, the rpm will surge back and forth (high-low-high-low, etc) when the throttle is in the mid-range area (not full throttle and not at idle).

I have heard a few theories from the guys at my field: "It's the servo-activated kill switch...disconnect it and it will stop." I disconnected it, and it is still there. Another said that "It's a Fuji....they do that until they are broken in." Another suggested that the low speed needle wasn't set right.

I don't know what would be causing it. It's just a little disconcerting when I'm on base leg ready to turn final and the thing is surging like crazy until I finally cut it to idle.

Any suggestions?

Thanks,

Rich