Pro-Pulse Prop Question

T

Tony Ferris

New member
I have twin Honda 40's on a CD-22 and wonder if anyone else has such a configuration. I'd like to get a couple of Pro-Pulse props and just wondering which exact model to get. I spend most of my time cruising Lake Powell at an elevation of about 3600-3650'. I asked Bill and El by email since they have that configuration, but their boat is in storage and he doesn't remember the exact model number. He suggested I post here to see if anyone else might have a similar configuration. Probably a 10.4" 11-17 pitch, but I figure it would be a good idea to have some other input. Thanks
 
I don't have a 22, but I did use a Pro-Pulse prop. I don't know what I hit, but it didn't make much of a noise, never saw or really felt it. Sheared 3 blades right off that prop.

I was in-between Dent and Yaculta Rapids, north of Desolation Sound. Found a place to change the blades out, but vowed never again would I depend on a plastic prop for my main prop.

Boris
 
journey on":17ysps09 said:
. . .
I was in-between Dent and Yaculta Rapids, north of Desolation Sound. Found a place to change the blades out, but vowed never again would I depend on a plastic prop for my main prop.

Boris
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Whoa! That is not a good place to lose power!
 
Tony

I have the same set up as you and use the pro-pulse props part number 6902. Have been very pleased with them and unlike Boris have hit bottom and other objects with and never lost all the blades, in fact have never lost more then one blade in any single hit and then only once. Most hits very closely equal the damage I use to get when making contact with an object on the old original aluminum props. Think the difference might be the much less force of the 40 hp motor compared to Boris's 150 hp.

Jay
 
Thanks for the replies to all. I'll have to look at the specs on the 6902. The main thing I'm looking for is something that works at the elevation I'll spend most of my time. I don't think I'll too much higher than that, but I live in Colorado, so you never know, I might actually put my boat on a local lake sometime. I like the idea of being able to adjust things for where I am. I'll take a look at the 6902 and see what the specs say. I was hoping Bill would get to his boat sometime soon since he spends a bunch of time at Lake Powell too. Either way, I think the Pro-Pulse is probably a great option as long as I don't hit something hard. I've bent a couple of props pretty good, so the odds of that happening are probably pretty high. I'll have to keep my fingers crossed. Thanks again.
 
Tony, they are adjustable and I have used them from sea level to Lake Yellowstone at 8000 feet and from very heavily loaded to light and even at Lake Powell too. Lake Powell is pretty tame boating compared to places I've used them in Canada and Southeat Alaska.

The beauty of the propulse adjustable pitch prop to me is the ability to quickly change the pitch or single blades if needed and being they have safely propelled us through the kind of waters and places they have leaves little doubt in my mind they should work well for you at Lake Powell

Jay
 
The thing I have never understood is the physics of props. The 6901 and 6902 each have the same range of pitch, the only difference being the diameter - one is 10.4" and the other 11.5. Seems like the larger diameter would give you more power, but I'm not quite sure that's correct. Maybe it provides more drag and slows you down. I probably need a refresher in physics anyway.

Nice to know they work well all the way up to Yellowstone elevation. Since I want to try going to Alaska eventually, having you tell me Lake Powell is tame makes me think I better not pass that one along to my wife. :D
 
Tony

Looked at the Propulse web site http://www.olds.com.au/marine/propeller ... llers.html and I see your point. I just went with their recommended prop for the Honda 35 to 50hp 4 stroke and that is the 6902 and like I said it worked well for us.

Sure didn't mean to denigrate Lake Powell boating just wanted to emphasize how it has worked out for us in some very remote no quick back up help cruising where we spend considerable time in shallow water areas. Of course the advantage of the twins in the shallow water exploring is being able to have one motor up and saved for back up if the other does hit something really hard. One can choose stainless props and really reduce the chance of prop damage but it in turn increase the chance of damaging the lower unit. This and the quick change of only the damaged blades at around $20 per with the ability to fairly quickly adjust pitch makes the Propulse a winner to me.

Jay
 
I understand completely about what you say about LP. Most of our boating was always on our little 30' houseboat. We've been in some storms that we thought were life ending. One in particular was what prompted my wife to finally tell me no more boating on Lake Powell until we were in a C-Dory. Guess there are some positives to being in a nasty storm!

In the C-Dory, you'd just sit there and bounce around not too worried. Big difference in the craft you're in. I don't think there is anything Lake Powell has to offer that would do in a C-Dory unless you did something stupid.

As for the ProPulse props, I just wanted to make sure I got the right one, I was already sold on the idea of something I could change pitch on. Stainless might be nice in some environments, but I sure wouldn't want to hit something solid with one.

Thanks for the input, now I just have to go find the cheapest price, which shouldn't be too hard with a few searches.
 
We had ProPulse props on the twin 40s on our CD22 (2003 - 2004), and then foolishly again on the BF150 on the CD25 (2005 until 2007) Although we were happy with the performance, we were not happy with their propensity to break off and strand us. The thread on that is here. The title of the thread tells it all.
 
Tony,

In the PNW and SE Alaska we have a lot of wood debris in the water. I took my 22 Cruiser to SE and back and that first year I bent three aluminum props on debris.

The second year I fitted a Stainless Steel prop. Although I did run over stuff in the water, the prop acted like a wood chipper and did not damage itself. I ran that same SS prop for 13 more years in the PNW, I never damaged the prop, and never had to send it in for repairs.

Hitting a rock with a SS prop can transfer enough energy from the prop to the gears in the lower unit and explode the gearcase. In that case a plastic prop that sacrifices itself would be preferred.

Another consideration is how would you change out the blades if you are in cold water? Putting the boat on the beach and standing in 50 degree water to change the prop may not be an option.

From my own experience in the PNW, my opinion is that damaging the blades on debris is more likely than striking a rock and damaging the gearcase. This may be the opposite of what is more likely in Lake Powell.

So, you pay your money and you take your chances!
 
Tony Ferris":2ciqahbf said:
The thing I have never understood is the physics of props. The 6901 and 6902 each have the same range of pitch, the only difference being the diameter - one is 10.4" and the other 11.5. Seems like the larger diameter would give you more power, but I'm not quite sure that's correct. Maybe it provides more drag and slows you down. I probably need a refresher in physics anyway.
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Tony-

The larger diameter prop will indeed transfer more power, but you engine only has so much to provide.

The bigger the prop diameter, the more solid the bite. That is to say, the less slip there will be. Slip is the difference between the theoretical and actual speed forward based on the pitch of the prop and the rpm at which it's being being turned.

Some slip is a positive thing, because it allows the motor to rev up further into its power range, where more torque and power are made. Once the boat hull speed rises, the slip percentage will go down, and all will be fine.

The problem with having too much diameter and therefore too much bite, is that the gearing is too solid and too tall, and the motor can't rev up into its best power producing rpm range.

It like being locked in 3rd gear or overdrive in a car. And even there, in a car, the torque converter provides some slip so, likewise, the motor can rev up into the power band.

So the smaller diameter prop indeed has its advantages over one that's too big, producing useful slippage.

On the other hand, too small a diameter prop would always slip too much and the motor would rev too easily and never have enough bite to fully transfer all the power the motor can produce into forward thrust and the maximum resultant speed.

So some slip is a good thing, with about 10-15% being a good average. Light runabouts and speedboats usually benefit from less, and heavy cruisers and houseboats more.

Hope this helps!

Joe. :teeth :thup
 
Actually, that wasn't more than I ever wanted to know. That put into words what I actually thought about the whole thing. I just hadn't had it explained well. It was much appreciated. I went with the 10.4 and found them for something like $180 somewhere and then $99 at West Marine. I didn't bother searching the world, the $99 seemed like a reasonable deal. Now, I just have to wait until May when I get to finally go back to Powell again. Then, the end of August when hopefully I can retire and go lots of other places. I just hope gas isn't $5/gal. I always wanted to go to Alaska and probably won't be able to afford it. Guess I'll find out if having a plastic prop is a good or bad thing too. I think there's a lot of truth to it being a bad thing on something in the 150hp and up range. I'm willing to give it a try on a couple of 40hp motors.

Thanks to all for helping me out. Bill, if you've been reading this, I won't be stalking you with so many questions now. Thanks to you too!
 
And the end of our story on the ProPulse for the BF150, with a couple of new extra blades. We offered the prop and blades for FREE here and had no takers. They ended up going in the garbage...that's a few $$$ I wish I had back.

All I can say is "good luck." They WILL break off on your BF40s too, it is just a matter of when, not whether I would say. You just need to hope you lose the blades on only one engine, and you are not in a tight spot where you need lots of power.

Resurrect this thread after you have a year's experience, it will be interesting to see how it goes!

 
One thing to remember is that SS props flex very little. Aluminum props flex a moderate amount, and plastic props flex a good deal. I prefer to have my prop keep its shape, and remain effecient. We have never had a problem with either aluminum or SS props at Lake Powell. In Florida we use only SS props. In the PNW and Calif (S. Calif and Delta) we used both Aluminum and SS props--never had any problems. I purchased a Pro Pulse as a back up--and put it on once--I was not happy with the performance.

In fact the only two problems I have had had with props, as spun hubs, or in a bravo III, and a 1" stick got caught between the two counter rotating props--that was enough to chip a gear tooth at an idle--and shortly all of the gears went. It was cheaper to buy an entire lower leg than rebuild the gears (that would not be true for an outboard.
 
Pat Anderson":178umqvr said:
And the end of our story on the ProPulse for the BF150, with a couple of new extra blades. We offered the prop and blades for FREE here and had no takers. They ended up going in the garbage...that's a few $$$ I wish I had back.

All I can say is "good luck." They WILL break off on your BF40s too, it is just a matter of when, not whether I would say. You just need to hope you lose the blades on only one engine, and you are not in a tight spot where you need lots of power.

Resurrect this thread after you have a year's experience, it will be interesting to see how it goes!
Click to expand...

I too wouldn't use them on a 150hp motor, but would counter your bad luck with the Propulse on the BF40 with our own of perhaps good luck. Larry H recalled his bending three aluminum props in one SE Alaska cruise and I bent up several too on our first trip north in 2003. Then on our 2004 cruise I changed to Propulse mid trip. Since then with over 4000 miles in SE Alaska and thousands more mostly running on remote lakes with only depth sounder and no electronic charts have only lost one blade and that was on a chunk of ice in front of LaConte Glacier and yes there have been plenty of hits on debris and the bottom. In seven years of cruising I've replaced perhaps a dozen blades due to chips and end tips missing. Think the cost of using aluminum or stainless would have been much higher without the advantage of pitch change.

Jay
 
It's good to see somebody exuding such confidence! I'll do my best to tell you what kind of experiences I have with them.

So... if you didn't want a ProPulse prop, what WOULD you put on two BF40's you wanted running at about 3700' elevation? I have some 10.5" aluminum props that I think are 11 pitch. They take a lot of work to get barely up on a plane. It gets expensive experimenting, so I guess the ProPulse will fall in that category too, another experiment.
 
Forgot about one other blade loss when I hit a rock on Yellowstone Lake. Was in front of the very picturesque Lake Hotel and Jo-Lee was taking video from land of the C-Dory in heavy chop in tight turns at speed. Had my Dad with me and in talking to him was not paying enough attention to shore distance. At that time in 2005 was still using the I believe there called McPherson River Running prop protectors. Hit the rock hard enough that it broke off half the skeg and protector and still only lost one Propulse blade. The loss of the one blade will cause a vibration but in an emergency could continue on with both motors.

Tony, the confidence only comes from the years of experience of them working out so well, but I will concede the stainless is even a better way to go other than the chance of lower unit damage. Would even now seriously consider going stainless even with the increased chance of lower unit damage if it wasn't for the cost of in my case of having to run to many different sets for the elevation changes.

Jay
 
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