This question is for those familiar with max prop.
I had the Sail-craft of Oriental install the new prop. They also installed 3/4 inch through hull fittings to help the engine run cooler. I can now cruse at 3100 rpm (wide open) without overheating. But my top speed is only 6 knots as measured by GPS. Propeller is 17" three blade.
The performance you describe does not sound satisfactory. But before anything else is said - do you have the standard W40 engine / Paragon direct 1:1 drive gear box / and the RV 10 1:2 reduction V-drive?
What is the pitch on your Max Prop?
Carl
POG - Hull 118
I will re-post my reply with a bit more meat to it. Here goes:
The performance you describe does not sound satisfactory. But before anything else is said - do you have the standard W40 engine / Paragon direct 1:1 drive gear box / and the RV 10 2:1 reduction V-drive?
What is the pitch on your Max Prop? I am not familiar with this propeller, but I believe that the pitch is adjustable. If you have the W40 engine etc as described above a 17" diameter with a 12"pitch works great if you are after speed in smooth waters. You can expect 5 knots at about 1800 revs. If you are after a bit more power when conditions are challenging I would go for an 11" pitch.
6 knots at full throttle is not acceptable. You have to pitch up.
I also think that the 1/2" intake for the raw water is under-sized with respect to the capacity of the raw water pump and possibly the requirements of the engine. However, changing just the thru hull without getting rid of other 1/2" restrictions in the system, such as the oil cooler and the heat exchanger will not achieve anything.
Carl
POG - Hull 118
Ralph asked the question, this is Linda, he is in Oriental getting some work done on ROCKY. I will relay this info to him in a few minutes when I give him his wake up call. More later....