Originally Posted by Todd Grimley
I have a 7.3 m hurricane with a AD41-P 200hp to a tail shaft drive DP-E 290 duo prop, with 1:1.78 gear ratio in top gear box and lower leg gears. I have A4 props on it.
Boat weighs about 2150 kg.
it does 34 knots WOT at 3150 rpm! Motor max revs is about 3800 rpm.
So should I try different props or think about changing lower leg gears to 1:1.95?
Is anyone familiar with this set up.?
You can do either of these, prop change is usually cheaper. If you get to the end of prop pitch availability you can then change the lower section of the drive leg if you still require lower gearing.
However, whilst I prefer lower pitch props because I consider them more use for general boating, if your aim is to gain maximum speed, higher pitch props will me more efficient at higher speed.