You need to provide us with more info. Exactly what type and diameter and pitch is your present prop? You have plenty of engine (probably a Universal M25XP). If you cannot maintain about 5.5 or 6.0 knots at about 2500 rpm against a moderate headsea, perhaps your present prop has too much or too little pitch. If you like lots of blade area, and do not mind losing a knot of sailing speed potential, change to a 3 bladed prop. If your prop is factory stock, it is most likely a two blade fixed.
As long as you maintain enough tip clearance (about 15% of the diameter of the prop) where the blade is closest to the hull, you want as much diameter as you can.
If you lucked out and have a feathering prop courtesy of the prior owner, just have the pitch changed.
You did not say if you are able to fully rev up your engine to 2900 or 3000 rpm with the present prop.
And if the present prop has too little pitch, it revs up to peak rpm's easily but the boat never goes over 5. or 5.5 in smooth water....
Loren
(1988 Olson 34 with a Universal M25XP and feathering Martec Prop)
As long as you maintain enough tip clearance (about 15% of the diameter of the prop) where the blade is closest to the hull, you want as much diameter as you can.
If you lucked out and have a feathering prop courtesy of the prior owner, just have the pitch changed.
You did not say if you are able to fully rev up your engine to 2900 or 3000 rpm with the present prop.
And if the present prop has too little pitch, it revs up to peak rpm's easily but the boat never goes over 5. or 5.5 in smooth water....
Loren
(1988 Olson 34 with a Universal M25XP and feathering Martec Prop)
sailingdeacon
Member III
Campbell prop
If you want power and sailing performance, and need to keep the costs down, seriously consider the Campbell 3 blade prop. See it at http://www.westbynorth.com/ If you email the guy, he will call you back. My experience two years ago was great. He helped me with the custome made prop and delivered it in two weeks. The company is small and the prop has some very unique properties. MIT studies are available. But best of all it is only a little more costly than a 3 blade MIchigan. For power with a boat your size and engine you have, you need a 3 blade prop. - especially against wind/tide/chop - as we have in this area of N.C. I had similar problems with a previous boat until I got the Campbell - and noticed almost no extra drag. I now have a E34 with a 30 hp engine and a 3 blade maxprop.
If you want power and sailing performance, and need to keep the costs down, seriously consider the Campbell 3 blade prop. See it at http://www.westbynorth.com/ If you email the guy, he will call you back. My experience two years ago was great. He helped me with the custome made prop and delivered it in two weeks. The company is small and the prop has some very unique properties. MIT studies are available. But best of all it is only a little more costly than a 3 blade MIchigan. For power with a boat your size and engine you have, you need a 3 blade prop. - especially against wind/tide/chop - as we have in this area of N.C. I had similar problems with a previous boat until I got the Campbell - and noticed almost no extra drag. I now have a E34 with a 30 hp engine and a 3 blade maxprop.
http://www.martec-props.com/
They are just down the freeway a bit... dime 'em up and find out if yours can be re-pitched.
If not, they often have trade-in props and might put together a swap deal for you.
IIRC, you may be speaking to a helpful person named Sheila when you call; if so, tell her I said hello.
Loren
They are just down the freeway a bit... dime 'em up and find out if yours can be re-pitched.
If not, they often have trade-in props and might put together a swap deal for you.
IIRC, you may be speaking to a helpful person named Sheila when you call; if so, tell her I said hello.
Loren