Has anyone got any experience, good or bad having replaced the standard two blade propeller on the H34 with an "Autoprop" automatic variable pitch propeller.
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Autoprop and H34
Just recently someone indicated that they talked to Autoprop at a Boat Show and they were told that they didn't have a prop that would work on the 34. I know that there are a some boats where either the prop is too far from the strut or too close to work. Too far and the prop, which is much heavier than a bronze prop, cause oscillation and too close and it can't clear the strut. I suggest you call Autoprop. They are extremely helpful and they will tell you whether or not it will work. They certainly will know if they have done it before. I found them very professional and knowledgeable and honest. If it doesn't work, they'll take it back! chuckwolfe@mail.com
Just recently someone indicated that they talked to Autoprop at a Boat Show and they were told that they didn't have a prop that would work on the 34. I know that there are a some boats where either the prop is too far from the strut or too close to work. Too far and the prop, which is much heavier than a bronze prop, cause oscillation and too close and it can't clear the strut. I suggest you call Autoprop. They are extremely helpful and they will tell you whether or not it will work. They certainly will know if they have done it before. I found them very professional and knowledgeable and honest. If it doesn't work, they'll take it back! chuckwolfe@mail.com
Read the archives
There is a ton of information about this prop in the archives. I know it doesn't fit on the 380 :-((((( Bob Knott
There is a ton of information about this prop in the archives. I know it doesn't fit on the 380 :-((((( Bob Knott
Max Prop
I put a Max-Prop on my 99 340 and have no vibration problems, as I put it on when I first bought the the boat I can't compare it to the OEM prop. I back into my slip and it is great! If you want more info... http://www.pyiinc.com/ Regards Ski
I put a Max-Prop on my 99 340 and have no vibration problems, as I put it on when I first bought the the boat I can't compare it to the OEM prop. I back into my slip and it is great! If you want more info... http://www.pyiinc.com/ Regards Ski
Autoprop
I replaced the factory standard on my 410 with an Autoprop this summer. Per the other repsonses the people at Autoprop are extremely helpful and knowledgable. As far as performance, I get up 1-1.5 knots more speed at the same RPM (less fuel consumption) the boat backs up when in reverse and will do 9.5 knots at full throttle on calm water. Took a bit to understand how to stop the boat, since at an idle it still will move at around 2 knots. You can either thro it into reverse momentarily, or place in neutral and the prop forms a drogue and slows the boat down. Great prop. Bryce S/V Spellbinder
I replaced the factory standard on my 410 with an Autoprop this summer. Per the other repsonses the people at Autoprop are extremely helpful and knowledgable. As far as performance, I get up 1-1.5 knots more speed at the same RPM (less fuel consumption) the boat backs up when in reverse and will do 9.5 knots at full throttle on calm water. Took a bit to understand how to stop the boat, since at an idle it still will move at around 2 knots. You can either thro it into reverse momentarily, or place in neutral and the prop forms a drogue and slows the boat down. Great prop. Bryce S/V Spellbinder
Autoprop-H34 and Fuel Efficiency
I have an Autoprop on a 37.5 and I think it's great and it is fuel efficient but the RPM's your engine is rotating at is not an exact indicator of how fuel efficient it is. The RPM's will vary up and down when you have the throttle in any one position because the blade pitches itself according to the sea conditions. I can tell that my throttle throw is maybe 3/4 full when I am doing hull speed but when conditions start getting rough, I have to give it more throttle to attain hull speed. That is the only time I can increase RPM's after I attain hull speed. ChuckWolfe@mail.com
I have an Autoprop on a 37.5 and I think it's great and it is fuel efficient but the RPM's your engine is rotating at is not an exact indicator of how fuel efficient it is. The RPM's will vary up and down when you have the throttle in any one position because the blade pitches itself according to the sea conditions. I can tell that my throttle throw is maybe 3/4 full when I am doing hull speed but when conditions start getting rough, I have to give it more throttle to attain hull speed. That is the only time I can increase RPM's after I attain hull speed. ChuckWolfe@mail.com
hey bruce...
...can you tell me precisely which model autoprop you bought for your 410? i'm hoping to get one myself at my first haulout, which will probably be next summer. (hard to say, because my bottom paint seems to be holding up better than my factory prop.) hoping to buy mine at the spring boat show. johnsfarnsworth@yahoo.com
...can you tell me precisely which model autoprop you bought for your 410? i'm hoping to get one myself at my first haulout, which will probably be next summer. (hard to say, because my bottom paint seems to be holding up better than my factory prop.) hoping to buy mine at the spring boat show. johnsfarnsworth@yahoo.com
Acts almost like a governer
Chuck is absolutely right that the RPM is no an indication of engine power output or fuel efficiency with this prop, 'cause, just like a constant-speed airplane propeller, when you increase or decrease the throttle setting,, the pitch of the prop may increase or decrease while keeping the RPM (within limits) the same. The major problem, though, in this aircraft/boat analogy is that in a plane there is an actual governer that keeps the rpm exactly where you want it through changes in power output, and in the Autoprop, the hydrodynamic load on the prop seems to serve this function, so you can not select a prefered RPM... the prop "decides" and who knows if it makes good decisions!
Chuck is absolutely right that the RPM is no an indication of engine power output or fuel efficiency with this prop, 'cause, just like a constant-speed airplane propeller, when you increase or decrease the throttle setting,, the pitch of the prop may increase or decrease while keeping the RPM (within limits) the same. The major problem, though, in this aircraft/boat analogy is that in a plane there is an actual governer that keeps the rpm exactly where you want it through changes in power output, and in the Autoprop, the hydrodynamic load on the prop seems to serve this function, so you can not select a prefered RPM... the prop "decides" and who knows if it makes good decisions!
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