engine rpm @ cruise?

[Mike Pollard]

Don,

I reach a smooth cruise @ 1800 RMP. The only problem is My Tartan 27 only makes 4 knots at this RPM. Higher RPMs yeild more vibration, and more speed, but I am reluctant to go beyond what "feels" good.

MTP

PS: I am using the standard two blade prop, and have recently adjusted my clutch.

[Don Moyer]

Mike,

Assuming that the engine itself remains smooth above 1800 RPM while in neutral, I suggest that you inspect the drive train for things like misalignment between the engine and prop shaft couplings, bent prop shaft, worn out cutlass bearing, barnacles on the prop, bent prop blade, etc.

You might also check the rear thrust bearing in the engine by pulling sideways on the prop shaft immediately behind the engine to see if you can feel (or see) any lateral play between the output coupling of the engine and the engine itself.

Regards,

Don