While checking out the engine running on Maggie IV, I found it ran very smoothly in neutral, (on a hardstand). When I engaged forward and reverse, there was a fair amount of vibration and roughness as the shaft and prop spun. It has a two blade prop.
Is this normal when there is no load on the prop? The prop turns freely by hand when in neutral with no obvious free play in the bearing. The engine, gearbox, shaft and bearings have 41 hours on them although it has been sitting for six years on a hardstand.
Any ideas?