I recently developed a "roughness" or vibration in my 2007 Sting with 1,040 hrs. I would describe it as being like: one mag had been shut off; or like there was fuel blockage someplace; or like I was flying grossly uncoordinated; or like I was flying with a nasty quartering-from-the-rear crosswind. It seems to be somewhat intermittent and concentrated in the mid-RPM range of about 3,800 to maybe 4,600, but sometimes higher or lower. It does not manifest in the low range of about 2,000-2,800. It was NOT present for the last 125 hours and appeared rather abruptly--and seems to be getting gradually worse.
We have pretty much ruled out the usual stuff: carb balance (checked several times); gearbox (Bellview springs 125 hrs ago & just now shimmed--with smallest shim); engine mounts; & propeller (checked for tracking and re-torqued. Also, in response to some visible "weeping" out the top of the 2/4 float bowl, we replaced that bowl, bowl retainer spring, needle seat, and gasket; the 1/3 carb was only checked for debris in the bowl and none was observed. None of these things have solved or helped cure the problem.
Where would you suggest focusing next? :angry: :ohmy: :dry:
We have pretty much ruled out the usual stuff: carb balance (checked several times); gearbox (Bellview springs 125 hrs ago & just now shimmed--with smallest shim); engine mounts; & propeller (checked for tracking and re-torqued. Also, in response to some visible "weeping" out the top of the 2/4 float bowl, we replaced that bowl, bowl retainer spring, needle seat, and gasket; the 1/3 carb was only checked for debris in the bowl and none was observed. None of these things have solved or helped cure the problem.
Where would you suggest focusing next? :angry: :ohmy: :dry:
