I'm thinking of buying a Mac26X, '97-'99 vintage, powered by a 50 HP outboard. What is the speed that I can expect from it under power? I'd like four figures based on your performance numbers with the water ballast EMPTY.
1. The boat with a light load, two persons and a days worth of gear, cruise speed.
2. The boat with a light load, two persons and a days worth of gear, max speed.
3. The boat with a heavy load, four persons and weekend camping gear, cruise speed.
4. The boat with a heavy load, four persons and weekend camping gear, cruise speed.
The specific boats I'm looking at have Nissan 50s, but I'd like to hear about all brands of 50 HP outboards and the difference, if any, between a 50 HP two stroke and a four stroke. My primary interest is power cruising. If you think it makes a difference having the mast up or off when powering I'd like to know that too.
Also, if I were to replace the outboard with a four stroke, does anyone have experience with a larger engine; say up to 70 HP on the 26X?
Thanks for helping me make this decision.
Speed of Mac 26X under power?
Speed of Mac 26X under power?
Last edited by lhartje on Sat Mar 26, 2005 9:47 am, edited 1 time in total.
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smidnite
Me three! Our record speed on our X was 19.6. We could cruise at 15 or 16 but preferred the quieter operation at 12 or 13 knots when not in a hurry. First thing I would do with the Nissan is change the impellor if PO has not done so already. Keep the Nissan--It is bullet proof; starts every time; does not let you down in the middle of the shipping lanes. You can order the special prop from BWY or shape and balance the one you have for a smoother, less vibration operation. 
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Frank C
Your questions are pretty detailed and explicit. Nobody here has done full-on performance tests, that I've seen. Also, the "true" answers to your questions requires optimized prop on each different motor. My guess is that half of owners don't have an optimized prop - ergo, expect generalized answers - sometimes reports of max 15mph w/ a 50hp is due to this issue.
But Robert did some pretty detailed testing of props on his Suzuki 50. Lots of specifics about different props on that motor. Probably not a lot of speed difference betw 2 vs. 4 stroke, but the older 2 strokes were very noisy, operate best at top rpms, and burn twice as much gas. The advantage of 4-stroke is quietude and mid-range cruising.
That much said, some 4-strokes offer more advantages. The Mercury/Yamaha (Bigfoot versions) 50/60 use a 14" prop, all other 50s have maximum 12" prop diameter. The larger prop helps mostly with slow-speed control, and offers a healthier mid-range cruise. Other than the Bigfoot drives, you need to go up in size & weight to a 60/70 to find the 14" prop. You'll probably gain about 3 to 4 mph WOT with a 70hp. My 60hp (not optimized) does 21 WOT, 15 mph @ 3800 cruise speed.
You can search for "Robert" in the memberlist and then search for all of his posts. You'll find plenty of info on props much discussion on different outboards. You can also search on obvious keys, like "70" or "outboard" or "WOT," etc. There's tons of info in the archives if you have time to read. Good luck on that decision.
But Robert did some pretty detailed testing of props on his Suzuki 50. Lots of specifics about different props on that motor. Probably not a lot of speed difference betw 2 vs. 4 stroke, but the older 2 strokes were very noisy, operate best at top rpms, and burn twice as much gas. The advantage of 4-stroke is quietude and mid-range cruising.
That much said, some 4-strokes offer more advantages. The Mercury/Yamaha (Bigfoot versions) 50/60 use a 14" prop, all other 50s have maximum 12" prop diameter. The larger prop helps mostly with slow-speed control, and offers a healthier mid-range cruise. Other than the Bigfoot drives, you need to go up in size & weight to a 60/70 to find the 14" prop. You'll probably gain about 3 to 4 mph WOT with a 70hp. My 60hp (not optimized) does 21 WOT, 15 mph @ 3800 cruise speed.
You can search for "Robert" in the memberlist and then search for all of his posts. You'll find plenty of info on props much discussion on different outboards. You can also search on obvious keys, like "70" or "outboard" or "WOT," etc. There's tons of info in the archives if you have time to read. Good luck on that decision.
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smidnite
Tom Spohn wrote:Me three! Our record speed on our X was 19.6. We could cruise at 15 or 16 but preferred the quieter operation at 12 or 13 knots when not in a hurry. First thing I would do with the Nissan is change the impellor if PO has not done so already. Keep the Nissan--It is bullet proof; starts every time; does not let you down in the middle of the shipping lanes. You can order the special prop from BWY or shape and balance the one you have for a smoother, less vibration operation.
This is a deffinet, for a nice smooth sound.
Unfortunately, the forum database lost the thread with Robert's detailed prop testing, much of it specific to his (and my) Suzuki DF50, which due to its higher rpm, uses the same prop pitch as the higher-geared Honda BF50. IIRC, he got 20-21 mph unballasted and lightly loaded, and about 16-17 mph ballasted and more heavily loaded, at wide-open throttle (WOT), with the best props.
I may have read every thread in these archives
and when it comes to performance reports, it's hard to make comparisons. For one thing, some report speeds in knots and others in statute mph. That's easy enough to convert. However, some are in more bouyant saltwater, and others in freshwater. Some are at different altitudes from sea level. Some have bottom paint and some don't. Some are trailered boats with clean bottoms and others are moored with at least some growth. And everyone's definition of lightly and heavily loaded varies to some unknown degree.
Even the term cruise speed is vague. For best fuel economy, that'll be hull speed, roughly 6.4 knots or 7.4 mph. Higher cruise speeds result in the boat climbing its bow wave and greater fuel consumption. In the end, cruise speed will also depend greatly on your tolerance for outboard noise. That, as well as fuel consumption, is greater with the older technology carbureted two-strokes than the modern four-strokes or direct fuel-injection (DFI) two-strokes. Whatever the technology, that's probably not much more than 10-12 mph with 50HP.
The older Tohatsu/Nissan motors have a reputation for being bulletproof. To me, that means years of fuel-gobbling, noise, smell & smoke. YMMV.
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Moe
I may have read every thread in these archives
and when it comes to performance reports, it's hard to make comparisons. For one thing, some report speeds in knots and others in statute mph. That's easy enough to convert. However, some are in more bouyant saltwater, and others in freshwater. Some are at different altitudes from sea level. Some have bottom paint and some don't. Some are trailered boats with clean bottoms and others are moored with at least some growth. And everyone's definition of lightly and heavily loaded varies to some unknown degree.Even the term cruise speed is vague. For best fuel economy, that'll be hull speed, roughly 6.4 knots or 7.4 mph. Higher cruise speeds result in the boat climbing its bow wave and greater fuel consumption. In the end, cruise speed will also depend greatly on your tolerance for outboard noise. That, as well as fuel consumption, is greater with the older technology carbureted two-strokes than the modern four-strokes or direct fuel-injection (DFI) two-strokes. Whatever the technology, that's probably not much more than 10-12 mph with 50HP.
The older Tohatsu/Nissan motors have a reputation for being bulletproof. To me, that means years of fuel-gobbling, noise, smell & smoke. YMMV.
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Moe
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waternwaves
- Admiral
- Posts: 1499
- Joined: Wed Oct 13, 2004 8:18 pm
- Location: X less in North Puget Sound -have to sail other boats for a while
As an owner of a "bulletproof" nissan 50......96, yeah.....I can see that I am tired of it long before it is going to wear out.....lol....and it is noisy...
and like few others here....... I have plenty of nice orange peel bottom paint on..., full head, galley.....tripple the tankage of everything....and go loaded for bear.... (or at least able to rebuild civilization on any shore I wash up on.. ya know your running heavy when you are carrying 22 lbs of charts and guides.....lol), but mast down makes sense if you are motoring more than 30 miles....the time to raise and the time hang the boom will be recovered....and the boat does go faster with gear down....
my earlier posts delineate some heavily loaded month trips.....and even at those weights.....1-2 mph difference in speed with gear down and stowed..
I use the BWY modified pitch prop......leave it on almost all the time...and 90% of my running is in saltwater.....
and to get to 18....I have to be partial tanked, 2 onboard.....and very lightly loaded for a weekend.....and dink on deck, not aft.....she does not handle aft weight well....and slows perceptibly.
Enjoy..
Darren
and like few others here....... I have plenty of nice orange peel bottom paint on..., full head, galley.....tripple the tankage of everything....and go loaded for bear.... (or at least able to rebuild civilization on any shore I wash up on.. ya know your running heavy when you are carrying 22 lbs of charts and guides.....lol), but mast down makes sense if you are motoring more than 30 miles....the time to raise and the time hang the boom will be recovered....and the boat does go faster with gear down....
my earlier posts delineate some heavily loaded month trips.....and even at those weights.....1-2 mph difference in speed with gear down and stowed..
I use the BWY modified pitch prop......leave it on almost all the time...and 90% of my running is in saltwater.....
and to get to 18....I have to be partial tanked, 2 onboard.....and very lightly loaded for a weekend.....and dink on deck, not aft.....she does not handle aft weight well....and slows perceptibly.
Enjoy..
Darren
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Sloop John B
- Captain
- Posts: 871
- Joined: Sat Jan 03, 2004 2:45 am
- Sailboat: MacGregor 26X
- Location: Florida 'Big Bend'. 02x Yamaha T50
Gee lharje,
Didn't you get your video yet? Check it out. 24 miles an hour. If you want to go slower, you pull back on the throttle a little.
It's not expressed in knots because that's a smaller number and many prospective customers don't yet understand the conversion.
Anyway, the Mac enters the marina from right to left. It's rather startling because Mac owners have never witnessed anything like it.
The skipper's name is Jesus Martinez. He is 10 years old and weighs 85 pounds. He has on bathing trunks, a T shirt, and a baseball cap. He has a half bottle of San Miguel beer.
After you buy your boat and try it out, you will go back and watch the video again. This time you will notice that the Mac is devoid of any rigging and that it is empty. I mean the cushions, the table, the potty, the bilge covers... everything. You may also hear a voice over that for every one hundred pounds added, the Mac goes one mile per hour slower.
I computed this out starting at 24 miles an hour by weighing myself and my mate and all the stuff we bring on board. Ballast alone is 14 miles an hour. I was distressed to learn we should be going backwards.
Nonetheless, we are able to make headway, about like the guys above report.
Didn't you get your video yet? Check it out. 24 miles an hour. If you want to go slower, you pull back on the throttle a little.
It's not expressed in knots because that's a smaller number and many prospective customers don't yet understand the conversion.
Anyway, the Mac enters the marina from right to left. It's rather startling because Mac owners have never witnessed anything like it.
The skipper's name is Jesus Martinez. He is 10 years old and weighs 85 pounds. He has on bathing trunks, a T shirt, and a baseball cap. He has a half bottle of San Miguel beer.
After you buy your boat and try it out, you will go back and watch the video again. This time you will notice that the Mac is devoid of any rigging and that it is empty. I mean the cushions, the table, the potty, the bilge covers... everything. You may also hear a voice over that for every one hundred pounds added, the Mac goes one mile per hour slower.
I computed this out starting at 24 miles an hour by weighing myself and my mate and all the stuff we bring on board. Ballast alone is 14 miles an hour. I was distressed to learn we should be going backwards.
Nonetheless, we are able to make headway, about like the guys above report.
Having just purchased my used 98 Mac X with a honda 50 I used my GPS to record speeds at different rpms.
Using a prop that I dinged two of the three blades the first day out (ok I'm learning) and cruising on calm water with little to no wind on empty ballast and mast up with rolled up jib/furler I obtained the following results:
RPM - Average Speed (mph) - Top Speed
3000 - 7.3 - 7.5
3500 - 8.3 - 8.3
4000 - 8.9 - 9.0
4500 - 10.3 - 10.3
5000 - 12.5 - 12.5
5500 - 14.0 - 14.5
6000 - 15.4 - 16.6
Yesterday I was motoring in 1'-2' seas into the wind blowing 20 to 25mph
(yes Virginia, we can sail all year round in Canada, at least the tropics of Canada) and I obtained a maximun speed of 13.7mph at 6000 rpms and 10.6mph at 5500 rpms I think, (the log is on the boat).
As Moe pointed out, the weight of the boat etc. is subjective based on a number of factors.
Needless to say, I would expect the speed to be higher if I hadn't been an idiot and dinged the prop, but I plan to replace the prop and will be monitoring my speed on an ongoing basis if anyone is interested.
Larry
P.S. Is there a better pitched prop for the Honda 50 that I should be purchasing?
Using a prop that I dinged two of the three blades the first day out (ok I'm learning) and cruising on calm water with little to no wind on empty ballast and mast up with rolled up jib/furler I obtained the following results:
RPM - Average Speed (mph) - Top Speed
3000 - 7.3 - 7.5
3500 - 8.3 - 8.3
4000 - 8.9 - 9.0
4500 - 10.3 - 10.3
5000 - 12.5 - 12.5
5500 - 14.0 - 14.5
6000 - 15.4 - 16.6
Yesterday I was motoring in 1'-2' seas into the wind blowing 20 to 25mph
(yes Virginia, we can sail all year round in Canada, at least the tropics of Canada) and I obtained a maximun speed of 13.7mph at 6000 rpms and 10.6mph at 5500 rpms I think, (the log is on the boat).
As Moe pointed out, the weight of the boat etc. is subjective based on a number of factors.
Needless to say, I would expect the speed to be higher if I hadn't been an idiot and dinged the prop, but I plan to replace the prop and will be monitoring my speed on an ongoing basis if anyone is interested.
Larry
P.S. Is there a better pitched prop for the Honda 50 that I should be purchasing?
Being able to reach the motor's maximum rpm when lightly loaded is one sign of a good prop pitch. The second is being able to reach the lower end of the manufacturer's recommended wide-open throttle RPM range with a heavy load.
Keep in mind that when measuring speeds in conditions with wind and current, you need to make two runs in opposing directions and take the average.
These speeds seem a little low. Do you have the largest diameter prop that will fit on the Honda (somewhere around 12")?
Robert's post indicated either the Solas 3-blade stainless 12.25x9" or their 4-blade aluminum 11-7/8"x9" (available on the Honda website) performed best on his Suzuki DF50, and should also work for the Honda 50.
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Moe
Keep in mind that when measuring speeds in conditions with wind and current, you need to make two runs in opposing directions and take the average.
These speeds seem a little low. Do you have the largest diameter prop that will fit on the Honda (somewhere around 12")?
Robert's post indicated either the Solas 3-blade stainless 12.25x9" or their 4-blade aluminum 11-7/8"x9" (available on the Honda website) performed best on his Suzuki DF50, and should also work for the Honda 50.
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Moe
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nemo
- Engineer
- Posts: 143
- Joined: Sun Mar 20, 2005 4:39 pm
- Location: Aloha, Oregon, '05 M, Suz70, "Nemo"
Yesterday we finally had enough hours on the Suzuki 70 to give it a short burst up to full throttle. We had 4 people aboard, although that included 3 boys averaging about 80 lbs each. According to GPS we maxed out at 20.4 mph. That was at about 5000rpm. Prop is 3x13.75x13. In my haste I forgot to raise the rudders (extra drag) and I had full ballast.
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Duane Dunn, Allegro
- Admiral
- Posts: 2459
- Joined: Fri Jan 02, 2004 6:41 pm
- Sailboat: MacGregor 26X
- Location: Bellevue, Wa '96 26x, Tohatsu 90 TLDI and Plug In Hybrid Electric drive
- Contact:
Mine is a '96 with a Tohatsu 50 (They make the same motor for Nissan).
Speed with a light load (even though our light load is probably heavier than most), no ballast, our normal crew or 2 adults, 3 growing kids.
WOT is 17 knots (19.55 MPH)
Towing a tube, knee board, or skier is 15.5 knots (17.8 MPH)
Cruise speed depends on conditions, we run at primarily two speed ranges.
Slow cruise (able to talk in the cockpit) is 7-8knots (8-9.2 MPH)
Fast Cruise (too loud for normal conversation in cockpit) is 10- 12 knots (11.5 - 13.8 MPH)
Speed with a heavy cruising load (dinghy and 6hp motor, 2 coolers, lots and lots of stuff/food, 28 gallons gas, 10 gallons water, etc)
WOT is around 14-15 knots (16.1-17.2 MPH) depending on the load. Really loaded as we were for our 3-1/2 week trip last summer at WOT we could just touch 13 knots (14.9 MPH)
Even loaded we still tend to operate in the same cruising speed ranges. You will find the two stroke motor gets the same mileage at 4500 rpm as it does at 3500. Often faster is better provided the conditions allow it since you use the same gas either way. The boat has better directional contro lover 10 knots. The autopilot corrects about half as much as it does in the 7-8 range.
We have cruised quite a bit without the mast along. The boat will sit a bit bow high without the 120lbs of mast and boom on the foredeck. I'm sure there is some small difference, but I can't say I have really detected any speed increase without the mast. It does make a huge difference in the time at the launch however.
Towing the dinghy alone will take just over a knot off your speed, towing the dinghy with the motor on will suck just under 3 knots off our speed. If you want to cover ground, pull the dinghy up on the foredeck.
We are mainly power cruisers as well, I would guess 85-90% of our time under way is power cruising without ballast. So far we have put 1,173.33 Nautical Miles on the GPS log over the course of 169 hours 37 minutes for an average speed of 6.9 knots (7.9 MPH).
All speeds are from the GPS, current can make a big difference in actual ground covered. All speeds are knots as thats the only thing any boat should use since all the charts are in Nautical Miles.
I also run the BWY custom Tohatsu prop. It's about a 11.4 pitch according to them.
Speed with a light load (even though our light load is probably heavier than most), no ballast, our normal crew or 2 adults, 3 growing kids.
WOT is 17 knots (19.55 MPH)
Towing a tube, knee board, or skier is 15.5 knots (17.8 MPH)
Cruise speed depends on conditions, we run at primarily two speed ranges.
Slow cruise (able to talk in the cockpit) is 7-8knots (8-9.2 MPH)
Fast Cruise (too loud for normal conversation in cockpit) is 10- 12 knots (11.5 - 13.8 MPH)
Speed with a heavy cruising load (dinghy and 6hp motor, 2 coolers, lots and lots of stuff/food, 28 gallons gas, 10 gallons water, etc)
WOT is around 14-15 knots (16.1-17.2 MPH) depending on the load. Really loaded as we were for our 3-1/2 week trip last summer at WOT we could just touch 13 knots (14.9 MPH)
Even loaded we still tend to operate in the same cruising speed ranges. You will find the two stroke motor gets the same mileage at 4500 rpm as it does at 3500. Often faster is better provided the conditions allow it since you use the same gas either way. The boat has better directional contro lover 10 knots. The autopilot corrects about half as much as it does in the 7-8 range.
We have cruised quite a bit without the mast along. The boat will sit a bit bow high without the 120lbs of mast and boom on the foredeck. I'm sure there is some small difference, but I can't say I have really detected any speed increase without the mast. It does make a huge difference in the time at the launch however.
Towing the dinghy alone will take just over a knot off your speed, towing the dinghy with the motor on will suck just under 3 knots off our speed. If you want to cover ground, pull the dinghy up on the foredeck.
We are mainly power cruisers as well, I would guess 85-90% of our time under way is power cruising without ballast. So far we have put 1,173.33 Nautical Miles on the GPS log over the course of 169 hours 37 minutes for an average speed of 6.9 knots (7.9 MPH).
All speeds are from the GPS, current can make a big difference in actual ground covered. All speeds are knots as thats the only thing any boat should use since all the charts are in Nautical Miles.
I also run the BWY custom Tohatsu prop. It's about a 11.4 pitch according to them.
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Frank C
Nemo, your Suzuki 70 should get higher RPM wide open, but the rudders would definitely add tons of drag. It's definitely a no-no ... lift rudders at 6 mph or they're placed under enormous stress. Also will screw-up handling. Just guessing that a 12" pitch would be better.
Regarding Redcoat's 50 hp ... it's a no-no to run an unbalanced prop, especially at higher speeds. If you're not trying to get every last ounce of top speed, you'll probably love the power, handling and smooth feeling of the 4-blade, 9"pitch. I have similar performance tables somewhere on four different props. All were graphed into an Excel spreadsheet, now long-buried on the hard disk.
Ah yes - remember those days of prop testing, Dear? Steady the engine speed, estimate the bouncing speed range for Mate to record in a log. Step up to the next engine speed - do again, do again, do again. Now let's run opposite direction and re-record. When comparing the two runs for anomolies - hmmm - wonder what happened there, strange readings betw 3200 and 3800! Now run again to double check that speed range, but ... uh oh .... speed zone here, slow down! Dighies racing up ahead, gotta ease off or we'll swamp 'em. Uh oh - is that harbor patrol?
It takes an hour or two of monotony to compile those charts for a given prop, because you need to stabilize at each RPM before logging a speed, then do it again. When the Mate starts grumbiling ... well, let's fill ballast and hoist some sail. We can try swapping to the second prop next weekend, allright Hon? Once you find a prop you like, the rest becomes an academic sidenote. Performance testing is really boring. Sailing is much, much more fun!
Regarding Redcoat's 50 hp ... it's a no-no to run an unbalanced prop, especially at higher speeds. If you're not trying to get every last ounce of top speed, you'll probably love the power, handling and smooth feeling of the 4-blade, 9"pitch. I have similar performance tables somewhere on four different props. All were graphed into an Excel spreadsheet, now long-buried on the hard disk.
Ah yes - remember those days of prop testing, Dear? Steady the engine speed, estimate the bouncing speed range for Mate to record in a log. Step up to the next engine speed - do again, do again, do again. Now let's run opposite direction and re-record. When comparing the two runs for anomolies - hmmm - wonder what happened there, strange readings betw 3200 and 3800! Now run again to double check that speed range, but ... uh oh .... speed zone here, slow down! Dighies racing up ahead, gotta ease off or we'll swamp 'em. Uh oh - is that harbor patrol?
It takes an hour or two of monotony to compile those charts for a given prop, because you need to stabilize at each RPM before logging a speed, then do it again. When the Mate starts grumbiling ... well, let's fill ballast and hoist some sail. We can try swapping to the second prop next weekend, allright Hon? Once you find a prop you like, the rest becomes an academic sidenote. Performance testing is really boring. Sailing is much, much more fun!
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TampaMac
- Engineer
- Posts: 142
- Joined: Sat Apr 03, 2004 9:03 am
- Location: Port Richey FL 2002-26X Merc 60 4stroke
Well, I can make a maximum of a little over 23 mph.
This on a boat with no mast or rigging, pretty lightly loaded, and being pushed by a Mercury 60 horsepower 4-stroke. When I had my mast up I never went over 20 mph and usually around 17 to 18 mph.
To me it doesn't seem that I get much extra performance out of my 60 over guys who have the 50. It is the same motor with a different rating, maybe different fuel mapping or cam, I don't know but it seems to me that you should buy a motor with more cubes over one with less. The Merc 50 and 60 have the same and I think are the same.
This on a boat with no mast or rigging, pretty lightly loaded, and being pushed by a Mercury 60 horsepower 4-stroke. When I had my mast up I never went over 20 mph and usually around 17 to 18 mph.
To me it doesn't seem that I get much extra performance out of my 60 over guys who have the 50. It is the same motor with a different rating, maybe different fuel mapping or cam, I don't know but it seems to me that you should buy a motor with more cubes over one with less. The Merc 50 and 60 have the same and I think are the same.