Yamaha 25 h.p. (2-stroke or 4-stroke)??
- Legend 151
- Participant
- Posts: 16
- Joined: Wed Mar 18, 2009 1:55 pm
Yamaha 25 h.p. (2-stroke or 4-stroke)??
Hello All,
I have visted your site over the past years and finally joined, great bunch of information.
My question is this: I have a 14 foot Legend boat, short transom and my older motor was undersized. I am looking at a new motor and think I have settled on Yamaha 25 h.p.
But I am not sure what to do about 2-stroke or 4-stroke. I am on the Ottawa River and need some speed to get from site to site, but I generally troll.
Any help, comments, suggestions would be greatly appreciated.
I have visted your site over the past years and finally joined, great bunch of information.
My question is this: I have a 14 foot Legend boat, short transom and my older motor was undersized. I am looking at a new motor and think I have settled on Yamaha 25 h.p.
But I am not sure what to do about 2-stroke or 4-stroke. I am on the Ottawa River and need some speed to get from site to site, but I generally troll.
Any help, comments, suggestions would be greatly appreciated.
-
- Diamond Participant
- Posts: 4823
- Joined: Tue Jun 29, 2004 7:44 pm
- Location: Carlsbad Springs
the 4 stroke will be much better for you , less noise, less fumes. will slow right down for trolling.
When hell freezes over, I'll be there icefishing!!!
If you can't stand behind our troops,
Please feel free to stand in front of them!!!
Experience is that marvellous thing that enables you to recognize a mistake when you make it again
If you can't stand behind our troops,
Please feel free to stand in front of them!!!
Experience is that marvellous thing that enables you to recognize a mistake when you make it again
- misty-river
- Participant
- Posts: 16
- Joined: Sun Jan 13, 2008 10:08 am
- Erie-Eyes
- Silver Participant
- Posts: 549
- Joined: Tue Apr 12, 2005 8:12 pm
- Location: Ottawa (Blackburn Hamlet)
Welcome aboard and enjoy. With reference to your motor size - what is your boat's maximum HP rating - I would not go larger than stated HP limit, and for general use would prefer not go less than 75% of this limit ie if boat is rated for say 40 HP motor - look at motors between 30-40 HP for maximum performance. If you are planning on doing a lot of trolling, the 25 HP Yamaha 4 stroke should be a good choice in this example. Hope this helps.
- Legend 151
- Participant
- Posts: 16
- Joined: Wed Mar 18, 2009 1:55 pm
- Fishtraks
- Participant
- Posts: 95
- Joined: Mon Sep 24, 2007 11:09 am
- Location: North Gower, On
- Contact:
2stroke VS 4stroke....
The trend seems to be toward 4 strokes...less pollution on the water, no smoke, no mixing,cheap on fuel etc,etc..go for the 25HP 4stroke. I got a 14' Legend Prosport with floor and could only afford a 15 4 stroke...while it is adequate, I wish I'd gone to a 25 or 30. With all the extra gear (battery, fishfinder,gastank,anchor,etc), it takes a long time to get on plane with just me and the wife on-board(and that's loading everything forward). But as for noise etc....I'd definitely go with the 4 stroke. That's my 2 cents....regards....Fishtraks.
Since you troll a lot, I would get the 4 stroke for sure. In a 14 footer a 25 2 stroke may not idle down to your preferred trolling speed.
My neighbor has a 16 footer with a full floor, live well, etc (fairly heavy) and with the 25 Yamaha 2 stroke it is always on the upper end of where we would like to troll.
Another friend of mine has a 25 4 stroke Merc Bigfoot and it can slow right down. I am amazed at how quite it is too.
My neighbor has a 16 footer with a full floor, live well, etc (fairly heavy) and with the 25 Yamaha 2 stroke it is always on the upper end of where we would like to troll.
Another friend of mine has a 25 4 stroke Merc Bigfoot and it can slow right down. I am amazed at how quite it is too.
- bigpikemike
- Bronze Participant
- Posts: 254
- Joined: Sun Mar 22, 2009 5:39 pm
- Location: Aylmer, Quebec
ive got a 14ft princecraft 160 series no floor open back 2 bench and i put a 25hp 2stroke merc on it and its wicked fast...even did a lot of tubin and skiing with the kids with it...gas mileage sucks and the trolling is even worse...trolls good for musky but that is it...tried dragging bucks but finnally broke down and bought a 55lb thrust stern mount minn kota for it...i would recommend an electric for trolling....if ur not looking for speed me and the wife love switching the motor to our 9.9 johnson for our fishing trips....nothing will work better for fishing then that...but then its no good for real lond distance
- mikemicropterus
- Bronze Participant
- Posts: 411
- Joined: Thu Jan 12, 2006 10:33 am
- Location: Franktown
- Contact:
2 stroke vs 4 stroke

How does a motor that takes an extra revolution to make one power cycle troll slower than a motor that takes only one cycle to make power.....this is physics and until the law of gravity is repealed I don't think unless they come up with some kind of special software for the fuel/igniton mapping that any 4 stroke will idle lower than a 2 stroke...
I have a 9.9 that will idle all day at 450 rpm.....I have yet to see a 4 stroke idle below 650rpm but that doesn't say they can't BUT as the idle lowers so does the oil pressure and that it what keeps 4 strokes living there supposed long life......

Another falsehood.......emissions...a 2 strokes exhaust are 30 % lower in all the dangerous emissions than a 4 stroke produces......also if you were put in a room with a 2 stroke engine and a 4 stroke engine running the 4 stroke will kill you faster........ 4 stroke has higher SO CO and NO than a 2 stroke but a 2 stroke has higher HC count and I'm talking DI engine now not carbureted but even then they are still lower, but much higher HC
So I would buy the 2 stroke, it's cheaper to maintain, it's lighter better power to weight ratio, not as much impact on the environment no oil and filter to dipose of..not real cost savings as far as fuel goes unless you troll 70% of the time....a 4 stroke is 10 to 20% more in price and you will ahve to own it a along time to get that back in savings becasue it is negated by the oil changes and maintenance,,,heaven forbid it might need some head work in the future.....MOST 4 stroke as it gets slower in idle shakes more than a 2 stroke because of the counter balance weights are desigend to work at certain rpm and if you go beyond that design limit vibrations the result.....a 2 cylinder motor will vibrate more than a 3 cylinder motor, it's more balanced...more than a 4 cylinder...but not a good as a 6 cylinder

A 4 stroke to get the same performance as a 2 stroke needs more rpm and more displacement as much as 20% more and that is where the fuel savings are also negated, more RPM and more displacement means you will burn more gas a WOT than a comparable 2 stroke DI engine...
BRP has 20 and 30 hp DI engines this year as well as no service for 3 years......and I wouild consider an ETEC also....
Yammies are good motor but they have soft gearcases, I have seen many failures with small impacts so much so that the gearcase just disintigrates....there was even video from the factory that went around a few years ago. I showed a yammie gearcase fail with the first impact, the other manufacturer's motor failed after about 10 attempts....it wasn't a black motor...........
Mercs are good also but my choice is ETEC as I own a 2000 200hp Evinrude Fitch, and a 9.9 Evinrude supposedly a problem motor but now going on it's fifth season the only problem I had was a $150 TPS. I service it each season and have a really good mechanic....

So like I say if the 2 stroke is set-up properly it will idle slower than a 4 stroke,,it's physics........and gravity is hard to argue with....

- bigpikemike
- Bronze Participant
- Posts: 254
- Joined: Sun Mar 22, 2009 5:39 pm
- Location: Aylmer, Quebec
- Legend 151
- Participant
- Posts: 16
- Joined: Wed Mar 18, 2009 1:55 pm
thanks for the advice
thansk to all.............so with the motor weight taken into account and some really good information all around
i found a great deal on a new 25 h.p. yamaha 2-stoke and i get it next week
algonquin park lake trout opener here i come
i found a great deal on a new 25 h.p. yamaha 2-stoke and i get it next week
algonquin park lake trout opener here i come
That is an awesome motor....very dependable. Every time I have been to the Caribbean, 98% of the motors have been Yamahas. The locals are wide open every where they go and I am sure those motors see little to no maintenance.
However, if you plan a slow troll for the lakers you may wish to bring an electric motor with you or a drift sock / trolling plate.
However, if you plan a slow troll for the lakers you may wish to bring an electric motor with you or a drift sock / trolling plate.