Hi All. I am about to take ownership
of an aluminium yacht which has a 50hp Perkins
Prima deisel. She has a s/s Autostream S1 self-feathering prop with adjustable pitch
. Based on the rev counter, the pitch
has been set for the engines Maximum Rated Speed of 3,000rpm.
The thing I have noticed is that at 3,000rpm (per the guage), the yacht speed through the water
is only 5knts. Her displacement
is only 8.9 tons and I would have expected a higher speed for this "weight". The prop cavitates at revs higher than 3,000rpm so effectively there is no useable power left.
At the wharf, the engine
revs to 5,000rpm wide open throttle and not under load.
I don't know if such high revs (5,000rpm) are normal and am wondering if the rev counter is reading far too high engine
revs. My aim is to make sure the prop is adjusted properly for the engines Max Rated Speed of 3,000rpm. But I don't know if the gauges are reading rpm
Any constructive suggestions appreciated.