Mark Karagianis, When I tested the Piranha 13 pitch on my Suzukki DF50 on my Mac26X, it seemed to work well, but RPMs were low. Untill about 3/4 or 7/8 throttle, the prop suddenly lost grip and the RPMs went to the limiter. If opening the throttle very slowly the onset of this could be delayed, but wide open always had this problem.
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The Piranha 11 pitch went maybe 6900 RPM for me, pulled great at top RPMs but not good at all at low RPMs.
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IMO, it is very desireable to run a Suzuki DF50 at 6800 RPMs unballasted since that is necessary to allow for 6200 to 6400 RPMs with a light load and ballast full. WOT goes down below 5800 RPM (12 to 13 MPH) with ballast full in five foot chop outrunning a storm or pulling tow toys full of kids. My dealer and the Suzuki rep both told me the DF50 loves to run at those top RPMs. (these RPMs are using the Solas 3 blade 9 pitch slightly cupped stainless or 4 blade 9 pitch aluminum right out of the box) Remember you are selecting a single prop for two different boats, one very heavy and one much lighter.
Michigan/Piranha/Solas Props on Suzuki DF50, 26M
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Mark Karagianis
- Engineer
- Posts: 184
- Joined: Fri Oct 07, 2005 1:29 pm
- Location: Still trailering from Northridge, CA to MDR. 2005 M Suzuki DF50 "Definite Addiction"
Ok, I've ordered the Solas 4 x 11.8 x 9. This weekend I'll test it against the Piranha 3 x 12 x 13 and the Michigan 3 x 12 x 10. The Michigan produced the fastest loaded speed on my earlier tests; no one seems to have tested the Piranha on the M (hopefully I won't have the high speed blowouts seen on Robert's X model); and Robert's comments on the Solas convinced me to order the $260 prop. Stay tuned . . . . .
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Bobby T.-26X #4767
- Captain
- Posts: 906
- Joined: Mon Jan 05, 2004 10:48 am
- Sailboat: MacGregor 26X
- Location: Oceanside Harbor, CA
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Mark Karagianis
- Engineer
- Posts: 184
- Joined: Fri Oct 07, 2005 1:29 pm
- Location: Still trailering from Northridge, CA to MDR. 2005 M Suzuki DF50 "Definite Addiction"
Last weekend I tested the Piranha 3 x 12 x 13 and the Michigan 3 x 12 x 10. The Michigan (produced the fastest loaded speed on my earlier tests) yielded a reliable 12.5 fully loaded and 3 crew + extra fuel + ballast loaded; pulling the valve and emptying ballast yielded 15 knots at 6,300 RPM. We almost got run down on the way to Catalina Island by a 70' cruiser on autopilot - I moved over and tucked in behind him and powered right in his wake for 1 hour at 15 - 15.5 knots!
The 3 x 12 (actually 11.75) x 13 Piranha was a big disappointment, 12 knots empty at 5,900 RPM. (No high speed blowouts, just not enough blade area). So I'm keeping the Michigan 3 x 12 x 10 for most powering conditions; I'll just pull the ballast and get the 14 - 15 knots power cruising that I am looking for. And on the ramp, when I opened up the ballast valve, only a couple of drops of ballast water came out. I didn't think that the ballast would drain so efficiently in the water.
Now I have to test the Solas 4 x 11.8 x 9 that I have waiting on my desk!
The 3 x 12 (actually 11.75) x 13 Piranha was a big disappointment, 12 knots empty at 5,900 RPM. (No high speed blowouts, just not enough blade area). So I'm keeping the Michigan 3 x 12 x 10 for most powering conditions; I'll just pull the ballast and get the 14 - 15 knots power cruising that I am looking for. And on the ramp, when I opened up the ballast valve, only a couple of drops of ballast water came out. I didn't think that the ballast would drain so efficiently in the water.
Now I have to test the Solas 4 x 11.8 x 9 that I have waiting on my desk!
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Frank C
Glad your crew were comfortable - that's always a concern when I suggest motoring with ballast tank empty. But sounds as if you're including that in your repertoire now - considering fuel prices, it's almost a necessity.
Not sure that this is same on 26M, but when I open the ballast tank on the X and power-up, I can hang over the stern see the water gushing from the tank. A few minutes later it's perfectly clear when the tank has emptied ... the complete ballast valve rides fully above the water surface and it's obvious that ballast is no longer streaming out - so that's the time to close the gate.
Not sure that this is same on 26M, but when I open the ballast tank on the X and power-up, I can hang over the stern see the water gushing from the tank. A few minutes later it's perfectly clear when the tank has emptied ... the complete ballast valve rides fully above the water surface and it's obvious that ballast is no longer streaming out - so that's the time to close the gate.
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Mark Karagianis
- Engineer
- Posts: 184
- Joined: Fri Oct 07, 2005 1:29 pm
- Location: Still trailering from Northridge, CA to MDR. 2005 M Suzuki DF50 "Definite Addiction"
I still haven't been able to try the Solas - if anyone else is thinking about ordering this prop for a '05 and later Suzuki, make sure that Solas has the prop hub machined so that the inside of the hub will not rub the inside ridge of the lower unit. See white streaking.
What's distressing is that Solas knew about the problem ("we have had a few of these past 12 monthes after suzuki improved thier painting anticorrosion processes.") but is sending these out anyway.
I had the machining work done and now the prop will fit all of the way down onto the thrust washer. The machining needed is inside of the hub 1.5 mm deep, and 15 mm length in from the edge of the hub.
Solas suggested machining 0.5 mm depth and the hub still rubbed (see Lower Unit photo above). I had to make two visits to the machine shop to get it right. Can't wait to try it out . . . .
What's distressing is that Solas knew about the problem ("we have had a few of these past 12 monthes after suzuki improved thier painting anticorrosion processes.") but is sending these out anyway.
I had the machining work done and now the prop will fit all of the way down onto the thrust washer. The machining needed is inside of the hub 1.5 mm deep, and 15 mm length in from the edge of the hub.
Solas suggested machining 0.5 mm depth and the hub still rubbed (see Lower Unit photo above). I had to make two visits to the machine shop to get it right. Can't wait to try it out . . . .-
Frank C
grease the spline shaft
Mark Karagianis, that spline shaft looks quite dry of grease. I was told that it is important to use waterproof grease on the prop shaft to preserve your ability to remove the prop by preventing corrosion.
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Mark Karagianis
- Engineer
- Posts: 184
- Joined: Fri Oct 07, 2005 1:29 pm
- Location: Still trailering from Northridge, CA to MDR. 2005 M Suzuki DF50 "Definite Addiction"
Bummer! I tested the Solas 4 x 11.8 x 9 yesterday. I had smooth conditions at Lake Castaic (smooth for a Mac, not so for the speedboats & water skiers), three crew, and a light boat load, 6,800 RPM good for 12.5 knots. Empty.
Full, it was about 6,500 RPM and 7-8 knots. A huge disappointment. What's worse, it took a long time loaded to hook up, as the prop ventilated strongly. I tried changes in attitude by shifting crew & load, to no avail. The prop was really unuseable with full ballast.
At "speed" with the ballast empty, the engine - RPM would pulse erratically, with RPM dropping 100-200 down to 6,600. Again, experimenting with tilt and load made no difference.
So it seem that at this point, Piranha 3x12x11 generated the highest speed empty, but was poor loaded.
The Michigan 3x12x10 is the best prop, useable loaded 12.5 knots and empty at 15 knots.
I'm going to see if I can exchange the 9-pitch solas for the 10-pitch that Solas also sells. Or does anyone with a houseboat want to buy it? I don't get why I had such bad luck compared with Roberts' experience.
Mark
Full, it was about 6,500 RPM and 7-8 knots. A huge disappointment. What's worse, it took a long time loaded to hook up, as the prop ventilated strongly. I tried changes in attitude by shifting crew & load, to no avail. The prop was really unuseable with full ballast.
At "speed" with the ballast empty, the engine - RPM would pulse erratically, with RPM dropping 100-200 down to 6,600. Again, experimenting with tilt and load made no difference.
So it seem that at this point, Piranha 3x12x11 generated the highest speed empty, but was poor loaded.
The Michigan 3x12x10 is the best prop, useable loaded 12.5 knots and empty at 15 knots.
I'm going to see if I can exchange the 9-pitch solas for the 10-pitch that Solas also sells. Or does anyone with a houseboat want to buy it? I don't get why I had such bad luck compared with Roberts' experience.
Mark
Solas 4 blade prop
It is my opinion that if you can ventillate the 4 x 11.8 x 9 Solas Prop, you have an outboard mounted too high, or a big exhaust leak around the prop hub instead of through it. Maybe your centerboard was down? Something is wrong. Are you sure the prop you have is what your thik it is, check the markings on the prop.
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I suggest looking into your installation. Put a board or other straight long object flat against the hull bottom ahead of the outboard and measure how far below or above the hull bottom the cavitation plate of your outboard is. I think it should be an inch below, that's where my outboard ended up after I raised it one mounting bolt hole. The outboard on my Mac26X was originally mounted as far down as possible. I read on this disscussion that having the outboard one inch below the hull was best efficiency.
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I suggest looking into your installation. Put a board or other straight long object flat against the hull bottom ahead of the outboard and measure how far below or above the hull bottom the cavitation plate of your outboard is. I think it should be an inch below, that's where my outboard ended up after I raised it one mounting bolt hole. The outboard on my Mac26X was originally mounted as far down as possible. I read on this disscussion that having the outboard one inch below the hull was best efficiency.
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aya16
- Admiral
- Posts: 1362
- Joined: Fri Feb 18, 2005 6:29 am
- Location: LONG BEACH CALIF Mac M 04 WHITE
I feel for Mark as he has spent many hours researching and buying potential fixes for the Mac power boat problem. His time spent here has
allowed us all to benifit from his research.
I really do believe that for claimed performance on the Mac you need
a bigger engine. Running a new boat with a fifty hp engine lightly loaded
will give the impression that thats all you need. But I have run fifty hp engines on pure power boats in the 15 foot class and was always disapointed. The ideal place for a fifty is on a small boat in the 13 foot class. That said if Roger raised the recomended hp of the mac to 70
and advertised the same performance as the fifty now everyone would be happy. But if he does raise the rateing and also the performance figures then all the new owners will not be happy with the 70 when the real world loaded boat cant achieve those numbers.
Macgregor is in a bind, the Mac is a stable sailing and motoring platform
to a point and as long as they recomend the smaller engine the boat can be a little misused with out major problems. So for real world people that are responsible will have to settle for less. So that the couple of misused Macs wont end up killing some people.
Perfect example, and I dont want to put anyone down here but you provided me with something to make a point with and by looking at your video you must agree because you jumped to the helm at the end of the video. So please dont take offence. In another thread some one was showing the Mac at wide open throttle with no one at the helm. They had a sport pilot doing the steering I assume. Well in a motor boat with that
same thing happening and say the pilot turned off or quit for some reason
the power boat would turn a nasty circle possible ejecting a couple passengers that were not sitting down at the time...In the mac a major problem would have happened the boat would have gone on its side ejecting all then right itself and keep going because there are no contour seats with hold straps like a power boat has. everyone was standing except the girl and she still would have been ejected I think.
Now Im glad that didnt happen but if it did would Macgregor recommend against a self steering system? After you guys sued Mac for an unstable boat provided you lived.
My point to this is if your buying a new boat and you feel you know the limitations of this Mac and are capable of making common sence decisions
(like not going 23mph when even the cig. boats are doing 15 because of the seas.) Then get the 90hp motor. If you want to stay within the fifty range then get the 60 that is based on the same specs. as the 50, like the etech. But if your going with a 70 you might as well pop for the 90 as its the same engine with a little more power In most cases.
Because you have all that power doesnt mean you have to use it.
But if you do go with a 90 or bigger try to be very resonable about the fact its still a sail boat.
One problem or should I say good thing about the mac is its stability.
Mark said it when the ski boats were in the churning water the Mac blew through it like nothing. This boat rides nice in the tuff stuff. That can give a false sence of security as if you had the power you could go a lot faster.
We need to think about this because the boat has nothing more than hard straight seats like a row boat. and we even stand at the speeds we can get out of our boats. Now even speed boats average around 30 miles an hour in my experiance rarely do they go sixty like they can. But the people in them are lower to the water and are in some kind of suportive seat.
I have seen someone take a power boat at around fifty and just whip the sterring wheel over put that boat on its side and skid for many feet sideways like that. No one was hurt and everyone thought it was cool well not everyone, but I wouldnt want to do that with a mac at 10 miles an hour. I think the Mac would go over. But the upward stability of the Mac
in a straight line and the way it rides in tough water gives a feeling of stability that would change in nano seconds if the boat was turned hard over at any speed.
So put the big engine on if you want the power but be carefull and dont use the auto pilot at full throttle and walk away from the helm. But in no way do I want to take the fun out of anyones trip and you guys looked like you were having the major mac fun. Being safe is one thing
but it doesnt take the place of knowing the limits of the boat. common sence is the key, we are thinking people and no one needs to be told to wear life jackets and when, I wear mine when I feel its time not when someone dictates or brow beats me into it. I feel the same about the power issue, You decide. Ill just give my opinion on the stability of the boat not if you should do it or not.
allowed us all to benifit from his research.
I really do believe that for claimed performance on the Mac you need
a bigger engine. Running a new boat with a fifty hp engine lightly loaded
will give the impression that thats all you need. But I have run fifty hp engines on pure power boats in the 15 foot class and was always disapointed. The ideal place for a fifty is on a small boat in the 13 foot class. That said if Roger raised the recomended hp of the mac to 70
and advertised the same performance as the fifty now everyone would be happy. But if he does raise the rateing and also the performance figures then all the new owners will not be happy with the 70 when the real world loaded boat cant achieve those numbers.
Macgregor is in a bind, the Mac is a stable sailing and motoring platform
to a point and as long as they recomend the smaller engine the boat can be a little misused with out major problems. So for real world people that are responsible will have to settle for less. So that the couple of misused Macs wont end up killing some people.
Perfect example, and I dont want to put anyone down here but you provided me with something to make a point with and by looking at your video you must agree because you jumped to the helm at the end of the video. So please dont take offence. In another thread some one was showing the Mac at wide open throttle with no one at the helm. They had a sport pilot doing the steering I assume. Well in a motor boat with that
same thing happening and say the pilot turned off or quit for some reason
the power boat would turn a nasty circle possible ejecting a couple passengers that were not sitting down at the time...In the mac a major problem would have happened the boat would have gone on its side ejecting all then right itself and keep going because there are no contour seats with hold straps like a power boat has. everyone was standing except the girl and she still would have been ejected I think.
Now Im glad that didnt happen but if it did would Macgregor recommend against a self steering system? After you guys sued Mac for an unstable boat provided you lived.
My point to this is if your buying a new boat and you feel you know the limitations of this Mac and are capable of making common sence decisions
(like not going 23mph when even the cig. boats are doing 15 because of the seas.) Then get the 90hp motor. If you want to stay within the fifty range then get the 60 that is based on the same specs. as the 50, like the etech. But if your going with a 70 you might as well pop for the 90 as its the same engine with a little more power In most cases.
Because you have all that power doesnt mean you have to use it.
But if you do go with a 90 or bigger try to be very resonable about the fact its still a sail boat.
One problem or should I say good thing about the mac is its stability.
Mark said it when the ski boats were in the churning water the Mac blew through it like nothing. This boat rides nice in the tuff stuff. That can give a false sence of security as if you had the power you could go a lot faster.
We need to think about this because the boat has nothing more than hard straight seats like a row boat. and we even stand at the speeds we can get out of our boats. Now even speed boats average around 30 miles an hour in my experiance rarely do they go sixty like they can. But the people in them are lower to the water and are in some kind of suportive seat.
I have seen someone take a power boat at around fifty and just whip the sterring wheel over put that boat on its side and skid for many feet sideways like that. No one was hurt and everyone thought it was cool well not everyone, but I wouldnt want to do that with a mac at 10 miles an hour. I think the Mac would go over. But the upward stability of the Mac
in a straight line and the way it rides in tough water gives a feeling of stability that would change in nano seconds if the boat was turned hard over at any speed.
So put the big engine on if you want the power but be carefull and dont use the auto pilot at full throttle and walk away from the helm. But in no way do I want to take the fun out of anyones trip and you guys looked like you were having the major mac fun. Being safe is one thing
but it doesnt take the place of knowing the limits of the boat. common sence is the key, we are thinking people and no one needs to be told to wear life jackets and when, I wear mine when I feel its time not when someone dictates or brow beats me into it. I feel the same about the power issue, You decide. Ill just give my opinion on the stability of the boat not if you should do it or not.
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Catigale
- Site Admin
- Posts: 10421
- Joined: Fri Jun 11, 2004 5:59 pm
- Sailboat: MacGregor 26X
- Location: Admiral .............Catigale 2002X.......Lots of Harpoon Hobie 16 Skiffs....Island 17
- Contact:
Art Reiders set my expectation when I bought my 2002 
with the BF 50 EFI..
"Hull speed is 7 mph, and this motor will let you double that, conditions permitting"
I got 23 mph unloaded WOT with the family aboard - now that we have loaded her with goodies I get about 15-16 at WOT.
I still meet the expectation that Art set.
Hope you are sailing full time on the other side, Art.
with the BF 50 EFI.."Hull speed is 7 mph, and this motor will let you double that, conditions permitting"
I got 23 mph unloaded WOT with the family aboard - now that we have loaded her with goodies I get about 15-16 at WOT.
I still meet the expectation that Art set.
Hope you are sailing full time on the other side, Art.
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Bobby T.-26X #4767
- Captain
- Posts: 906
- Joined: Mon Jan 05, 2004 10:48 am
- Sailboat: MacGregor 26X
- Location: Oceanside Harbor, CA
there was something in the original X video where Roger says:
"for every 100# of added weight, the speed drops by 1 mph".
that includes the weight of the captain (155 vs. 255), a full tank of fuel & water (8# to a gallon), the extra battery, anchor & rode...the list goes on.
it doesn't take much to get to 500# which equals a reduction of 5 mph.
plus: that 2 stroke tohatsu 50D was a "screamer" (vs. the slow, heavy, & clean burning 4-stroke 50's of today). for those of you that have it, you know what i'm talkin' 'bout.
i truly believe that the old tohatsu 50D got the original X to 23mph even though my Suzuki 50 never got me past 20 from day one in a stripped boat.
Bob T.
"DaBob"
'02X w/ '04 90-TLDI & '06 2.5-Suzuki
"for every 100# of added weight, the speed drops by 1 mph".
that includes the weight of the captain (155 vs. 255), a full tank of fuel & water (8# to a gallon), the extra battery, anchor & rode...the list goes on.
it doesn't take much to get to 500# which equals a reduction of 5 mph.
plus: that 2 stroke tohatsu 50D was a "screamer" (vs. the slow, heavy, & clean burning 4-stroke 50's of today). for those of you that have it, you know what i'm talkin' 'bout.
i truly believe that the old tohatsu 50D got the original X to 23mph even though my Suzuki 50 never got me past 20 from day one in a stripped boat.
Bob T.
"DaBob"
'02X w/ '04 90-TLDI & '06 2.5-Suzuki
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Mark Karagianis
- Engineer
- Posts: 184
- Joined: Fri Oct 07, 2005 1:29 pm
- Location: Still trailering from Northridge, CA to MDR. 2005 M Suzuki DF50 "Definite Addiction"
Robert, thanks for your suggestion to check the cavitation height. I know that my motor is set as low as possible; it would never occur to me to raise it as a fix for a ventilation problem. I have not had ventilation to speak of with any of the other props that I have tried. I will check this out tonight when I get home. And my centerboard and rudders were all of the way up, and the boat was lightly loaded, although my tanks were near full.
I wrote to Solas yesterday and described my results. They responded today (they are in Australia) and wanted to know if the water was very cold (it wasn't) 'cause apparently that matters too, and also suggested that I have the blades cupped. I remember that you (Robert) had said that it worked on your X model straight out of the box, and your stainless prop needed to be cupped.
It there anything to know about doing this? Are there degrees of cupping? Will I have to re-paint it afterwards? Can anyone in the LA area recommend a prop shop?
After I have had this prop machined and cupped, if it doesn't work I think that I'm going to have trouble returning / exchanging it. May have to sell it to someone with a X.
I'm sure glad that the sailing part is so good. But we couldn't sail on the lake; it would have been like being a loose dog out on the freeway, what with the lake past capacity, 1-hour waits to get into the ramp and 45-minute waits (in the water!) to get out, 45 degree shifting gusty winds, and 2,000 mainiacs going crazy all around us. We won't be doing that again soon, Diane was freaked out ("I'm NEVER doing that again!"). Those NEVERs are really hard to get by. We really got some good double takes & long stares, I don't think they have ever seen a sailboat on the lake.
There are sure a lot of weird things to learn about when you have a boat.
Mark
I wrote to Solas yesterday and described my results. They responded today (they are in Australia) and wanted to know if the water was very cold (it wasn't) 'cause apparently that matters too, and also suggested that I have the blades cupped. I remember that you (Robert) had said that it worked on your X model straight out of the box, and your stainless prop needed to be cupped.
It there anything to know about doing this? Are there degrees of cupping? Will I have to re-paint it afterwards? Can anyone in the LA area recommend a prop shop?
After I have had this prop machined and cupped, if it doesn't work I think that I'm going to have trouble returning / exchanging it. May have to sell it to someone with a X.
I'm sure glad that the sailing part is so good. But we couldn't sail on the lake; it would have been like being a loose dog out on the freeway, what with the lake past capacity, 1-hour waits to get into the ramp and 45-minute waits (in the water!) to get out, 45 degree shifting gusty winds, and 2,000 mainiacs going crazy all around us. We won't be doing that again soon, Diane was freaked out ("I'm NEVER doing that again!"). Those NEVERs are really hard to get by. We really got some good double takes & long stares, I don't think they have ever seen a sailboat on the lake.
There are sure a lot of weird things to learn about when you have a boat.
Mark