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DuckWise
Joined: 19 Jul 2010
Posts: 16
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 Posted: Tue Aug 03, 2010 11:32 pm Post subject: Vintage OutBoard Motor Weight? |
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| I am assuming that a 50s era Outboard Motor weighs more than a late model Outboard of the same Horse Power? So say a 1955 50 HP motor is going to be heavier than a 90s-2010 50 HP motor? So if My mid 50s Buccaneer is rated for a 50HP motor Max, and the hull is still solid I should be able to put a newer model 50 HP on the boat no problem right? |
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squirrelboydeluxe
Joined: 12 Jan 2010
Posts: 24
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| Posted: Thu Aug 05, 2010 4:02 pm Post subject: Outboard motor weight |
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A 1961 Mercury 50hp motor is approx 130lb.
A 2010 Evinrude 50hp ETEC (a two stroke) is 248lb.
Any modern FOUR STROKE you can name will be heavier than the ETEC.
Hope this helps. George B |
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DuckWise
Joined: 19 Jul 2010
Posts: 16
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| Posted: Thu Aug 05, 2010 6:50 pm Post subject: Re: Outboard motor weight |
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| squirrelboydeluxe wrote: | A 1961 Mercury 50hp motor is approx 130lb.
A 2010 Evinrude 50hp ETEC (a two stroke) is 248lb.
Any modern FOUR STROKE you can name will be heavier than the ETEC.
Hope this helps. George B |
Hmm thats interesting so using a modern motor you would be limited to say a 25HP motor weight wise anyway?? I guess if a guy could find a good running 50-60s era 40-50 HP that would work. I have 1972 Mercury 20 HP motor on the boat now I wonder what it weighs? I have found an old owners manual but I cant find a shop manual that might list the weight. |
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Samster
Joined: 26 Aug 2009
Posts: 17
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| Posted: Fri Aug 06, 2010 6:23 pm Post subject: |
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So is the maximum hp rating for the boat based only on the weight the transom can hold?
Does the amount of thrust that the transom can withstand play any factor? What about max speed of the boat?
I seem to remember reading somewhere on this forum about how in 1957 the biggest outboard motor you could get was 35hp. So Crestliner made the max hp for some of their boats 70hp so you could mount two 35's. I might be remembering wrong on that though  .
Interesting about the weight of different motors though. Where do you find that information? My 57 Buccaneer says max hp of 70 so I too am wondering how much weight that is and what kind of hp my boat can handle. |
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DuckWise
Joined: 19 Jul 2010
Posts: 16
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| Posted: Fri Aug 06, 2010 6:50 pm Post subject: |
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If you compare a modern boat of the same type and very nearly the same dimensions a SmokerCraft Alaskan DLX15, is just a tad shorter and a few inches wider at the transom than the old Buccaneer, and it is rated for a 35hp. If I had to guess the Buccaneers might be a little stouter? They are built with the same gauge aluminium.
I would be comfortable hanging a modern 35-40HP 2 stroke on my old boat. |
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Samster
Joined: 26 Aug 2009
Posts: 17
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| Posted: Sat Aug 07, 2010 1:42 am Post subject: |
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Interesting topic Duckwise.
Doing a little research I came up with http://www.old-omc.de/
Some great old brochure pictures in there. (I love watching the evolution of boating through the photos)
If you look through the brochures it shows that in 1955 a 25hp Johnson weighed 125 lbs.
I would guess that in 1955 a Buccaneer like yours might have dual 25hp engines on there. Just like some of those photos. Maybe why 50hp max rating given by Crestliner???
If this is the case maybe a good guess is that your boat is good for close to 250lbs.
Next, here is a link http://www.nadaguides.com where you can find all the weights of outboard motors right back to 1975. (Go to "Boats" and then "Outboard motors" to find it.)
There is a definite difference between 2 stroke and 4 in terms of weight but depending on manufacturer an old 2 stroke vs a new one might not be that different.
However, I've also read that somewhere along the line (80's) they began measuring horsepower differently. So a new engine rated at 50hp produces more than an old 50hp. Something like 10-20%
Using weight and hp differences as primary factors, I also agree. I think your Buccaneer would do well with a 30-40hp motor.
I see that your boat is set up for tiller steering. My 57 Buccaneer which is the same dimensions as your boat and is set up for steering at the front. If you are considering redoing your boat totally original or have other plans I understand. However if not, I strongly suggest you should consider moving your controls to the front. My Buccaneer absolutely flies with just a 30hp Yamaha. Even with two people sitting up front and just the gas tank in the back the boat rides high and dry. (Most small aluminums with two in the front seem to plow). The boat cruises over light chop and seems far more seaworthy than it first appears. Everyone who rides in my boat is amazed at the performance.
I think you are going to really love your new boat.
Good luck |
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OutBdNut
Joined: 27 Mar 2005
Posts: 593
Location: Minnesota
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| Posted: Sun Aug 08, 2010 9:45 pm Post subject: |
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| Samster wrote: |
However, I've also read that somewhere along the line (80's) they began measuring horsepower differently. So a new engine rated at 50hp produces more than an old 50hp. Something like 10-20%
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Horsepower used to be measured at the powerhead, now it's measured at the propeller shaft, so you get the effects of power loss from the driveshaft, water pump, and lower unit gears. So a motor has to put out more to have HP measured at the propshaft. This started with different models and manufacturers in the mid to late 1980s depending on the motor. Word I heard is that the US companies had to do this because the Japanese were doing it and the US motors of the same HP did not perform as well.
The difference is more noticeable on smaller motors. For example, the 9.9 HP Mercury (introduced in 1986) will run circles around the 9.8 it replaced and also the old 9.5 Johnson/Evinrudes. (I've run all these models on my fishing boat). As HP gets bigger, the noticeable effect becomes less.
Now if you are talking Mercurys from the early 1950s, they intentionally under-rated their motors so they would outperform others of the same advertised HP. The 10 Mercury Hurricanes from the early 1950s put out 16 to 18 HP! After that, OBC ratings became the norm bringing uniform measuring methods.
If you compare 4-strokes with 2-strokes, the 2 strokes have more low end torque for pulling up skiers and planeing the boat off faster, as the two stroke motors have the pistons firing every stroke, vs every other stroke for the 4-strokes.
As to motor weight, I grew up driving Dad's 1958 Voyager14 rated for 60 HP, and over the years he had it, we had a 20, 30, 40, and 60 on it. The 60 was a 1965 - 4 cylinder Johnson. It weighs about the same as the other 4 cylinder 50 to 90 HP Johnsons/Evinrudes of the 1960s and 1970s (somewheres well over 200 pounds). It ran fine on the boat, but it was a bit heavy to the back. Not a big deal if you didn't have all your passengers in the back as well, and learning to handle it with the extra weight was not a big deal.
As far as weight of 4-strokes go, the notable exceptions to 4-strokes weighing a lot more than 2-strokes are the Honda 20 HP and the Yamaha 25 HP 4-strokes. They have weight in the same ballpark as 2-strokes. Other 4-strokes around 25 to 40 HP, are 3 cylinders and this adds more weight.
If you find your motor is too heavy, you can offset that some by putting the gas tank and battery up front. If you get too much weight to the rear, your trailer wheels may have to be moved to the rear a bit if that is possible on your trailer to keep some weight on the trailer tongue. I have one boat where I have to move the gas tank to the front (and have it nearly full) when the trailer is not hooked to my truck, or the trailer tips backward due to negative tongue weight! A cement block works too!
One final note - if you look into the first 4 cyl 50 HP Johnsons/Evinrudes from 1958/59, they had a huge lower unit that was like dragging a big club through the water - and are argueably the biggest gas hogs ever made. From 1960 up, all 4 cyl Johnsons and Evinrudes had a much slimmer lower unit and it made a huge difference in gas use and performance.
Dave
_________________
57 Commander 12 Custom Deluxe 550
58 Commodore 14 Speedster (modified)
58 Cadillac Riviera 14 split deck
Dozens of old outboards |
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