Background - I am going to buy either a 3 blade feathering Max-Prop or a AutoProp. Prop will be put on a 450 with a 76 hp Yanmar. Max-Prop quoted a 18" diameter. AutoProp quoted a 20" diameter. Questions - If you have either a 450 or 460 with a Yanmar 76 hp engine AND also one of the props, please tell me the following: 1. Prop make & size: 2. Crusing speed & RPM: 3. Do you have vibriation ? 4. Any problems associated with your prop ? 5. If the Max-Prop - Pitch you are using: 6. Would you change your buying decision if you could ? In the best of worlds, it would be gear to try both on the same boat before the buying decision, but in the real world not possible. Let me say thanks, to all for the help and informatation in advance.
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460 Max prop
D ear Gordon: I have a H460 with the three blade feathering Max Prop. The prop size is 18 inch and the actual setting that was dialed in is recorded on my log kept in the boat which I will get for you. The setting used was to duplicate a a pitch of 17. My cruising RPM is about 2800 which gives a speed between 8.0 and 8.4 depending on sea conditions. Maximum RPM with the present pitch setting is 3700, with a speed of 9 knots. The engine only has 25 hours of operation time but so far no vibration or problems. In fact the drive train is very smooth and quiet. In reverse, the boat is very responsive with no prop walk. The only draw back is the price tag of $2800. But, considering the size of the boat, the prop makes her very easy to manuver and well worth the investment.
D ear Gordon: I have a H460 with the three blade feathering Max Prop. The prop size is 18 inch and the actual setting that was dialed in is recorded on my log kept in the boat which I will get for you. The setting used was to duplicate a a pitch of 17. My cruising RPM is about 2800 which gives a speed between 8.0 and 8.4 depending on sea conditions. Maximum RPM with the present pitch setting is 3700, with a speed of 9 knots. The engine only has 25 hours of operation time but so far no vibration or problems. In fact the drive train is very smooth and quiet. In reverse, the boat is very responsive with no prop walk. The only draw back is the price tag of $2800. But, considering the size of the boat, the prop makes her very easy to manuver and well worth the investment.
460 Max prop
D ear Gordon: I have a H460 with the three blade feathering Max Prop. The prop size is 18 inch and the actual setting that was dialed in is recorded on my log kept in the boat which I will get for you. The setting used was to duplicate a a pitch of 17. My cruising RPM is about 2800 which gives a speed between 8.0 and 8.4 depending on sea conditions. Maximum RPM with the present pitch setting is 3700, with a speed of 9 knots. The engine only has 25 hours of operation time but so far no vibration or problems. In fact the drive train is very smooth and quiet. In reverse, the boat is very responsive with no prop walk. The only draw back is the price tag of $2800. But, considering the size of the boat, the prop makes her very easy to manuver and well worth the investment.
D ear Gordon: I have a H460 with the three blade feathering Max Prop. The prop size is 18 inch and the actual setting that was dialed in is recorded on my log kept in the boat which I will get for you. The setting used was to duplicate a a pitch of 17. My cruising RPM is about 2800 which gives a speed between 8.0 and 8.4 depending on sea conditions. Maximum RPM with the present pitch setting is 3700, with a speed of 9 knots. The engine only has 25 hours of operation time but so far no vibration or problems. In fact the drive train is very smooth and quiet. In reverse, the boat is very responsive with no prop walk. The only draw back is the price tag of $2800. But, considering the size of the boat, the prop makes her very easy to manuver and well worth the investment.
460 Max prop
D ear Gordon: I have a H460 with the three blade feathering Max Prop. The prop size is 18 inch and the actual setting that was dialed in is recorded on my log kept in the boat which I will get for you. The setting used was to duplicate a a pitch of 17. My cruising RPM is about 2800 which gives a speed between 8.0 and 8.4 depending on sea conditions. Maximum RPM with the present pitch setting is 3700, with a speed of 9 knots. The engine only has 25 hours of operation time but so far no vibration or problems. In fact the drive train is very smooth and quiet. In reverse, the boat is very responsive with no prop walk. The only draw back is the price tag of $2800. But, considering the size of the boat, the prop makes her very easy to manuver and well worth the investment.
D ear Gordon: I have a H460 with the three blade feathering Max Prop. The prop size is 18 inch and the actual setting that was dialed in is recorded on my log kept in the boat which I will get for you. The setting used was to duplicate a a pitch of 17. My cruising RPM is about 2800 which gives a speed between 8.0 and 8.4 depending on sea conditions. Maximum RPM with the present pitch setting is 3700, with a speed of 9 knots. The engine only has 25 hours of operation time but so far no vibration or problems. In fact the drive train is very smooth and quiet. In reverse, the boat is very responsive with no prop walk. The only draw back is the price tag of $2800. But, considering the size of the boat, the prop makes her very easy to manuver and well worth the investment.
Max -Prop v. Auto Prop
The difference is size between the two is because of the way they are engineered. I lean towards Autoprop because I don't have to worry about diving and fiddling getting the correct pitch. Better motor sailing with the Autoprop and better fuel economy. The sail efficiency of Max-prop is better according to specs. If Auto-Prop won't work satisfactorily on your boat, they will take it back. Auto-Prop cause a vibration problem on some models because of the distance between the prop and the strut. Too much and the weight causes vibration (much heavier than a bronze prop). Too close and the blades hit the strut. Mine vibrated originally but then it stopped after my boat was cleaned so I believe that something must have either grown onto the prop causing it to go out of balance or grown kept one of the blades from opening all the way. Right now, no vibration, much better fuel economy, backing, sailing and I motor at hull speed. It wasn't cheap but it was probably one of the best investments I made in my 37.5. chuckwolfe@mail.com
The difference is size between the two is because of the way they are engineered. I lean towards Autoprop because I don't have to worry about diving and fiddling getting the correct pitch. Better motor sailing with the Autoprop and better fuel economy. The sail efficiency of Max-prop is better according to specs. If Auto-Prop won't work satisfactorily on your boat, they will take it back. Auto-Prop cause a vibration problem on some models because of the distance between the prop and the strut. Too much and the weight causes vibration (much heavier than a bronze prop). Too close and the blades hit the strut. Mine vibrated originally but then it stopped after my boat was cleaned so I believe that something must have either grown onto the prop causing it to go out of balance or grown kept one of the blades from opening all the way. Right now, no vibration, much better fuel economy, backing, sailing and I motor at hull speed. It wasn't cheap but it was probably one of the best investments I made in my 37.5. chuckwolfe@mail.com
AutoProp
I purchased a new 376 two years ago and installed an autoprop the beginning of last year. What a difference!! I achieved about 3/4 of a knot increase in speed using the same RPM over the old fixed two blade prop. Backing up has been a joy with the autoprop. The biggest plus of the self pitching autoprop comes when you are motoring in heavy weather. I have noticed very little decrease in speed through five foot seas. I'll be buying another one for my next boat.
I purchased a new 376 two years ago and installed an autoprop the beginning of last year. What a difference!! I achieved about 3/4 of a knot increase in speed using the same RPM over the old fixed two blade prop. Backing up has been a joy with the autoprop. The biggest plus of the self pitching autoprop comes when you are motoring in heavy weather. I have noticed very little decrease in speed through five foot seas. I'll be buying another one for my next boat.
Ian, why's does your's fit?
I can't understand Autoprop for the life of me. As I've told my tale of woe here before I won't belabor the point, but I chose and Autoprop for all the reason Ian just mentioned. I got it installed on my 380 but it didn't fit. Kept hitting the strut. Autoprop finally admitted it didn't fit the 380 which I can't understand since it fits the 376 (see Ian's response) and they are essentially the same boat. Drives me nuts :-(((( Of course there are people here who've been witness to my madness in my posts for years.
)) Glad it worked out for you Ian, I'm on to a Maxprop as soon as I get up the dough! Bob Knott H380
I can't understand Autoprop for the life of me. As I've told my tale of woe here before I won't belabor the point, but I chose and Autoprop for all the reason Ian just mentioned. I got it installed on my 380 but it didn't fit. Kept hitting the strut. Autoprop finally admitted it didn't fit the 380 which I can't understand since it fits the 376 (see Ian's response) and they are essentially the same boat. Drives me nuts :-(((( Of course there are people here who've been witness to my madness in my posts for years.
)) Glad it worked out for you Ian, I'm on to a Maxprop as soon as I get up the dough! Bob Knott H380MaxProp on a 450
I installed a MaxProp on my 450 when it was new, so I can't comment on how it compares to the stock prop. I originally set the pitch to that recommended by PWI, and it was quite wrong. Speed maxed out at about 6 knots at high engine rpm, although it was excellent in all other respects, particularly lack of prop walk in reverse. I then changed the pitch and it is much better, although I think it is still not quite right and could do with another adjustment. (I'm not on the boat at the moment, so I can't tell you the actual settings. Email me if you want them: eldreds@hotmail.com.) You may want to consider spending the extra few hundred dollars for the version which can be adjusted underwater without tools as you'll save the cost of haulouts if you need to make an adjustment. On the other hand, you have to haul out and grease the prop once a year anyway, so perhaps the extra cost isn't worth it. Your call.
I installed a MaxProp on my 450 when it was new, so I can't comment on how it compares to the stock prop. I originally set the pitch to that recommended by PWI, and it was quite wrong. Speed maxed out at about 6 knots at high engine rpm, although it was excellent in all other respects, particularly lack of prop walk in reverse. I then changed the pitch and it is much better, although I think it is still not quite right and could do with another adjustment. (I'm not on the boat at the moment, so I can't tell you the actual settings. Email me if you want them: eldreds@hotmail.com.) You may want to consider spending the extra few hundred dollars for the version which can be adjusted underwater without tools as you'll save the cost of haulouts if you need to make an adjustment. On the other hand, you have to haul out and grease the prop once a year anyway, so perhaps the extra cost isn't worth it. Your call.
Ian's Strut Interference Problem
Ian - in your post you mentioned the prop was hitting the strut. If there is clearance between the prop and the rudder is it possible to have a new shaft made that will provide the needed clearance? If the clearance is small perhaps a spacer between the flanges? It seems the cost of a new shaft should be a lot less than changing to a different prop.
Ian - in your post you mentioned the prop was hitting the strut. If there is clearance between the prop and the rudder is it possible to have a new shaft made that will provide the needed clearance? If the clearance is small perhaps a spacer between the flanges? It seems the cost of a new shaft should be a lot less than changing to a different prop.
Auto-Prop didn't work on my P42
I tried three different Auto-Props on my 1993 Passage 42 before I gave up. I had several discussions with the very nice folks at Auto-Prop, one at the Miami Boat Show last year, and others on the phone before I purchased the Prop. I was assured several times that it was a straight bolt on for my boat. Wrong! As my boat sat in the slings, I found the Auto-Prop hitting the strut big time. I called and was informed I needed to install a Drive-Saver to space it out 2”, and I would have to shave the strut. OK, $200 later, and a couple of extra days in the boat yard, but it would be worth it. I’ll cut to the chase, I had serious vibrations problems that three Auto-Props could not get rid of, and I would like to add that my engine even after me telling them it would turn 3800 at max rpm, you can’t change the pitch on an Auto-Prop. I did like some of the features of the Auto-Prop, but I went to the Max-Prop and that sucker works very well without any vibration. Also, I could set the pitch I wanted to place my max rpm at 3400 as is called for by Yanmar. Chuck Vincent Eagle’s Nest II Cypremort Point, LA.
I tried three different Auto-Props on my 1993 Passage 42 before I gave up. I had several discussions with the very nice folks at Auto-Prop, one at the Miami Boat Show last year, and others on the phone before I purchased the Prop. I was assured several times that it was a straight bolt on for my boat. Wrong! As my boat sat in the slings, I found the Auto-Prop hitting the strut big time. I called and was informed I needed to install a Drive-Saver to space it out 2”, and I would have to shave the strut. OK, $200 later, and a couple of extra days in the boat yard, but it would be worth it. I’ll cut to the chase, I had serious vibrations problems that three Auto-Props could not get rid of, and I would like to add that my engine even after me telling them it would turn 3800 at max rpm, you can’t change the pitch on an Auto-Prop. I did like some of the features of the Auto-Prop, but I went to the Max-Prop and that sucker works very well without any vibration. Also, I could set the pitch I wanted to place my max rpm at 3400 as is called for by Yanmar. Chuck Vincent Eagle’s Nest II Cypremort Point, LA.
P-42 Autoprop
In reply to Chucks problem, I have no anwer, but I had an 18' Autoprop installed on my 1992 P-42 with no problems. It works very well except for a vibration at 1800-1850 rpm. (So I just don't run it at that speed.) We just returned from a long trip down the ICW and had a really nice time of it (except I hate the ditch). The main problem I had was learning to dock and sail the boat all over again because of the increased slipperiness.. it won't slow down with just the reduction in power as with the fixed prop. Fuel consumpton was reduced and the 2400 rpm speed was reached at 2150 to 2200 rpm compared to the fixed wheel. If I am not mistaken, the sailing speed also increased by at least 1/2 knot or more in the same wind conditions. So far, the last two years have given me satisfactory service with this prop and it still looked like new at my haul out this month after scraping off some of the accumulated sea growth. There must be as many different opinions as boat owners about props, and I hope this helps... Dick
In reply to Chucks problem, I have no anwer, but I had an 18' Autoprop installed on my 1992 P-42 with no problems. It works very well except for a vibration at 1800-1850 rpm. (So I just don't run it at that speed.) We just returned from a long trip down the ICW and had a really nice time of it (except I hate the ditch). The main problem I had was learning to dock and sail the boat all over again because of the increased slipperiness.. it won't slow down with just the reduction in power as with the fixed prop. Fuel consumpton was reduced and the 2400 rpm speed was reached at 2150 to 2200 rpm compared to the fixed wheel. If I am not mistaken, the sailing speed also increased by at least 1/2 knot or more in the same wind conditions. So far, the last two years have given me satisfactory service with this prop and it still looked like new at my haul out this month after scraping off some of the accumulated sea growth. There must be as many different opinions as boat owners about props, and I hope this helps... Dick
Max prop pitch
The max prop setting on my H460 with the 76 hp engine is a blade angle of 26 degrees which equates to a pitch of 16.6. The X setting is V and the Y setting is B. This pitch angle allows the engine to achieve maximum RPM.
The max prop setting on my H460 with the 76 hp engine is a blade angle of 26 degrees which equates to a pitch of 16.6. The X setting is V and the Y setting is B. This pitch angle allows the engine to achieve maximum RPM.
Autoprop R Us
We put an autoprop on our 430 when new, so I also can't compare it to the two bladed standard prop now decorating my garage. I'm very pleased with it, and on this boat there is plenty of clearance and no excess vibration that others have experienced at any RPM. This prop sets its own pitch based on a balance of centrifugal force and hydrodynamic load ant any particular RPM, and while I understand that concept, I wonder if this pitch is the most effective or efficient pitch at all times... I worry about machinery that's smarter than I am <g>! You'll like it! George Kornreich
We put an autoprop on our 430 when new, so I also can't compare it to the two bladed standard prop now decorating my garage. I'm very pleased with it, and on this boat there is plenty of clearance and no excess vibration that others have experienced at any RPM. This prop sets its own pitch based on a balance of centrifugal force and hydrodynamic load ant any particular RPM, and while I understand that concept, I wonder if this pitch is the most effective or efficient pitch at all times... I worry about machinery that's smarter than I am <g>! You'll like it! George Kornreich
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