Topic: What is the "BEST" power to weight 25hp made ?

This topic has 10 replies, 9 voices, and was last updated 9 years, 6 months ago by mightymite.

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May 29, 2015 at 11:19 pm #1631
mightymite
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US Member
Hello All, I am considering a larger HP for my Crestliner Commodore. I currently have a 1958 Johnson 18 hp I often run on it. But, who doesn’t want more speed ? My problem is the weight. I just don’t like getting much over a hundred lbs. Just getting too hard to lift these days. I noticed that the 18hp Johnson that was 22 c.i. was eventually reworked to produce 25hp. At 81lbs that is pretty remarkable.Anyone know about this motor, or have a suggestion of a good runner that is light weight ?
May 29, 2015 at 11:50 pm #17163
fleetwin
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US Member - 2 Years
I would consider one of the OMC 32CI 25-35hp engines with thru hub exhaust.
May 30, 2015 at 3:04 am #17171
benchrascal
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The comment about the thru hub exhaust motors is pretty much right on the bean .I used two piece lower units on my commercial motors for years because that is how johnson sold them .The first thru hub 25 hp (same exact engine except thru hub) blew the others away ,absolutely no comparison .It enabled me to fish farther ,carry heavier loads ,plane more quickly and all on less gas.truly a remarkable change.That being said the two piece lowerend is much easier if you have to do a water pump ,gear work etc. Your choice but if speed is the issue borrow a thru hub and prepare to be amazed.
May 30, 2015 at 3:09 am #17172
garry-in-michigan
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Lifetime Member
Both use a 31 cubic inch powerhead. The through the hub exhaust is on the 35 horse model – about 112 pounds. The 25 horse model is (like the early ’50s OMC 25) slightly over 100 pounds.
May 30, 2015 at 4:17 am #17178
dan-in-tn
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US Member
Being a forever OMC fan as you may be you can not over look the Mercury 18, 20, 25hp of the ’90 and beyond till the 4 strokes. That little motor was the lightest in its class with great power. Now it became famous for it chrome bore block early and later it’s Mercosil block. These motors were rumored to not be repairable, but could be sleeved if chrome bore and the Mercosil blocks could be bored. It was absolutely critical that the Mercosil block not suffer oil starvation or an overheat. Something no engine should have to go through with proper maintenance. I’m not trying to sell you a Mercury motor, but you asked for the best power to weight ratio and you would have to consider the Mercury on that basis. The motor is small and compact.

Dan in TN
May 30, 2015 at 5:43 am #17184
frankr
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US Member
Not what you asked for at all, but lemme put in a plug for my 1984 35hp. I have often said it is the best outboard I’ve ever personally owned (in that HP class). I mention it because you said you want more power. This will give you that, for sure. And without being ridiculously heavy. I agree the thru-hub gearcase is one secret of it’s performance. Mine swings a 15" SST prop and turns 6000 RPM and goes like the proverbial Striped Ape.

Having said all that, I have to say avoid the early thru-hub motors with the water inlets on the front. Bad news. Once they moved the water inlets to the side, good news.
May 30, 2015 at 3:27 pm #17199
equad99
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i have a model 810 commodore, and if you want to stay with a 1950s outboard a merc mark 25 might be worth looking at, it will run circles around my 18 horse omc….the merc spec chart says they weigh 75 pounds…speed wise its comparable to my early johnson rd 25 horse…art b
May 30, 2015 at 4:14 pm #17200
mightymite
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US Member
Thanks for all the great feedback. It sounds like the 32 c.i. OMC may be the way to go. I,m not totally eliminating the Mercury ideas. I used to have a nice Mark 25(I swapped it at a meet). I was not entirely impressed with that motor. It actually was not quite as fast as my Wizard WG7. I always suspected that huge prop might be part of the performance issue.So unless a Mercury falls in my lap, I may start looking for a 32. 🙂
May 30, 2015 at 4:23 pm #17201
seakaye12
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US Member
The older (80’s vintage) Tohatsu/Nissan 2 stroke 25HP is mentioned a lot in discussions relating to power vs weight and over-all reliability. I’ve never owned one…..but that’s what others have said….

It looks like Yamaha made a 25HP 2-stroke that weighs 105 lbs; not bad 🙂
http://www.outboard-engine.com/enginesp … cordID=234

The Tohatsu 25 and 30HP 2-strokes weigh 115 pounds.
http://www.outboard-engine.com/enginesp … cordID=161
May 30, 2015 at 4:43 pm #17203
outboard315
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Being a mercury fan I would go with a 1962 Merc 250.
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