25 Hp 2 vs 4 stroke comparison?

[Wee Hooker]

Hi all, been searching here but have yet to find more than bits and pieces of info.
I'm getting ready to buy a new open 16' Aluminum boat rated for a 40hp tiller. I figure something in the 25-30 hp range should push it along nicely for my needs. However, i'm caught in the 2 vs 4 stroke delema. I've always had and like 2 strokes. What i like about 2 strokes is that they are light and easy to troubleshoot, repair, maintain.
However, I keep hearing i should go 4 stroke to get a quieter and more efficient motor. My reservations revolve around the facts that:
1)a 4 stroke weighs about 50% more in this size range so i realy then need to go to a 30HP to compensate(I think).
2) I don't know squat about their reliability but assume that repairs and maintneance are going to be harder or forced to be farmed out?
3) Cost differential between a 25 2 stroke and a 30 4 stroke is about $1K. Not sure if it's worth it.
Thoughts from mechanics/ owners on the topic ( includeing which models to look for/avoid) are very welcome.
Also, is there a good online tutorial on the pros/cons of small 4 strokes anywhere?
Thanks in advance!

 

[JB]

Re: 25 Hp 2 vs 4 stroke comparison?

Like you, I find that the advantages of a 4 stroke get pretty thin when you get into smaller outboards, and if they don't have EFI they weigh less, but are still big and heavy beside a 2 stroke.

Because (and only because) of the proliferation of "green" laws that are banning 2 strokes from more and more waters I would still go for a 4 stroke and probably look for one with EFI, which gives better economy than carbs.

 

[steelespike]

Re: 25 Hp 2 vs 4 stroke comparison?

Like you, I find that the advantages of a 4 stroke get pretty thin when you get into smaller outboards, and if they don't have EFI they weigh less, but are still big and heavy beside a 2 stroke.

Because (and only because) of the proliferation of "green" laws that are banning 2 strokes from more and more waters I would still go for a 4 stroke and probably look for one with EFI, which gives better economy than carbs.

First I believe they are banning motors that don't meet STAR regs.
Of course this means carbed 2 strokes.
Keep in mind that Evinrude Etec has a 35 cube 25 and 30 hp DFI 2 stroke that meets or exceeds all STAR regs.Lightest is 146 lbs..Are available with electric start.power trim and tilt.Etec is allowed on restricted Lake Tahoe.

 

[mthieme]

Re: 25 Hp 2 vs 4 stroke comparison?

Wow. That's a beast. If memory serves, my Merc 25 is 400cc (2 stroke) and a dainty 112 #. Looking at a Yamato 302 next !
I'm with JB, personally, with a smaller engine, I would go 2 stroke.

 

[JB]

Re: 25 Hp 2 vs 4 stroke comparison?

Didn't know about that etec, Steelespike.

I do think that many of the "green" laws don't talk about emissions, just 2 stroke vs. 4 stroke. Worth checking out.

That etec would be more economical and cleaner than a carbed 4 stroke. A good option, except that I buy pre-owned engines several years to 30 years old. Not likely to find an etec 30 in that class.

 

[Wee Hooker]

Re: 25 Hp 2 vs 4 stroke comparison?

I have 5 small ( 2-8 hp) 2 strokes in the garage that I use rarely and bought in some state of "used". ( HAd 1 5 hp evenrude 4 stroke and sold it off quickly. Too heavy and lacked power.) What I'm intending to do here is replace my "go to" fishing skiff that I bought (all) new in 95'. This one will also likely stay with me for well over 12 years so I'm more concerned about getting what works best for me vs saving $. ( Although, $ is always considered.) Still one the fence but believe i will check out the Etec. Might be another option for what i want.


FWIW, motors i'm currently looking at are the Yamaha 25 2 stroke (about $3K)
and a Tohatsu 30 (about $4K), Have to go find a Evenrude dealer now.
Thanks

 

[steelespike]

Re: 25 Hp 2 vs 4 stroke comparison?

Didn't know about that etec, Steelespike.

I do think that many of the "green" laws don't talk about emissions, just 2 stroke vs. 4 stroke. Worth checking out.

That etec would be more economical and cleaner than a carbed 4 stroke. A good option, except that I buy pre-owned engines several years to 30 years old. Not likely to find an etec 30 in that class.

I guess it will be several years before you cou;ld consider an Etec.And Im not sure if they are in the hands of the dealers yet.
Can't speak for the other lakes but Tahoe has some sort of official boats that are powered by Etecs I would assume lakes of size would admit motors that officially meet CARB/STAR requirements.

 

[pvanv]

Re: 25 Hp 2 vs 4 stroke comparison?

Had a customer with a similar boat, and an old 2-stroke OMC 35. Due to surgery, he couldn't pull-start it (comfortably) any more. Sold him a Tohatsu 30 (EFI) electric start. So he went to 4-stroke, 3-cylinder, electric start, and no choke. Weight is a tad more, but the benefits of no smoke, excellent low-end thrust, economy, convenience of not mixing oil, and quietness, far outweighed that. He loves it. One of my most satisfied customers.

 

[marquette]

Re: 25 Hp 2 vs 4 stroke comparison?

i have a 16ft lund rebel with a 30hp honda on it. i downsized from a 40hp yamaha 2 stroke on it because i needed to be able to troll slower than the yamaha could on this boat. i would definatly go with the 30hp. if i had known how well 4 strokes troll i would have gone to a 40hp. if i just used the motor to go from point A to point B and then either used an electric to move around or still fished i would go 2 stroke because of the simplicity, reliablility and number of good clean used motors available. but if i wanted to troll or pleasure cruise around the lake i would go 4 stroke. the quietness is worth every bit of extra purchase cost or maintaince alone. let alone the ability to troll. my 28hp johnson SPL has more hole shot than the 30hp honda and less mid range bog down. top end is pretty even after getting up on plane. WOT noise is about the same or maybe because of wind and ect. you don't notice much differance. i had to put trim and tilt on the Honda because it was a horse to handle with out it which added another 50lbs to the back of the boat and $400 less in my pocket. the 28hp is light enough to tilt easily by hand. the honda sips fuel compared to the 28. advantages and shortcomings to both.

 

[kandil]

Re: 25 Hp 2 vs 4 stroke comparison?

you should look for a Tohatsu 25HP 2 strokes and upgrade it to 30HP it is very easy and cheap

 

[Wee Hooker]

Re: 25 Hp 2 vs 4 stroke comparison?

How easy to convert the 25 to 30 (2 stroke.) ??

To be honest, I'm leaning towards the 4stroke despite my distrust of "new technology". 30 years of tinkering with 2 stroks puts them in my comfort zone.
Here's why: I can get a leftover yamaha 25 2 stroke electric for about $3000 but would need to add power tilt/trim anyway ( had hernia surgery and just don't want to be wrestling motors as I get past 50 summers.) That's another $500-$600 by my math.
Local dealer has new Tohatsu 25, electric, Power tilt/trim for $3750 installed. I can go to a 30 for another $450.

I figure the $200-$300 delta is worth it in agrivation, resale and fuel savings.
Only down side is I'm not convinced about reliability of the 4's vs 2's.
Maintenance/oil changes should be in the weeds as I don't put on 100 hrs /year.

 

[marquette]

Re: 25 Hp 2 vs 4 stroke comparison?

reliability becomes a relitive question. think about how long you have owned any outboard as your main motor. if you realize that you change motors every 7-8 years then looking for a motor that will last 25 yrs is a mute point because you are just looking for a motor for the next guy. if you bought your last main motor in 1983 and are still running it 20 times a summer then finding a motor to last 25 yrs is important. and to put a few things in perspective since 1983 manufactures have added: thru hub exhaust, electronic ignition, EFI, DFI, 4 stroke, VRO(or some form of oil mixing), and a host of other improvements to make outboards more user friendly. and with all the improvements has come the greater risk of component failure. today's environmentally friendly 2 strokes are almost as complicated as a 4 stroke. the 2 cylinder, carburated, magneto ignition, 50:1 tank mixed, bullet proof outboard that set the standard for reliability and endurance is gone. the comparison between 2 stroke vs 4 stroke today should be about performance, cost , weight, noise, polution and which technology will meet future evironmental restrictions better.

 

[Howard Sterndrive]

Re: 25 Hp 2 vs 4 stroke comparison?

Because (and only because) of the proliferation of "green" laws that are banning 2 strokes from more and more waters I would still go for a 4 stroke and probably look for one with EFI, which gives better economy than carbs.

Are you saying they will ban existing 2 strokes?

e.g. If he buys a 2 stroke today, in an area where it is legal to use, will they at some time in the future ban the use of it?
that would definitely hurt...

 

[pvanv]

Re: 25 Hp 2 vs 4 stroke comparison?

As a dealer and mechanic, here are my thoughts...

The 4-strokes are heavier because they have more parts -- the valve train, for example. These are tried-and-true designs that have been used on land since at least the 1960's, and are very durable. This debate reminds me of the questions that came up when points-and-condensers magneto ignition was supplanted by electronic ignition, or when electric chokes came on the scene. I'll take electronic ignition, thank you. No, you can't file the points on one of these new motors, but at the same time, there's no NEED to do that kind of maintenance.

Completely agreed that both the 4-strokes and the modern 2-strokes are similarly complex, and have electronics that weren't considered on the simple, 2-cylinder, premix, carbureted 2-strokes of the 1970's. For example: automatic oil mixing and similar technologies (on the 2-stroke), as well as ECU and EFI. The reliability of all these engines is similar, and is very good.

Most of us do more maintenance on all our outboards (both 2- and 4-strokes) than we do on our land-based motors, due primarily to operating in the marine environment. A 4-stroke will want occasional oil changes, which the 2-stroke will not. At your <100 hours a year, this can be done annually, when the LU lube is checked/changed. So that's not much of a factor.

As for resale value, there are both types of used-motor buyers: those that want the lighter weight and hole shot of the 2-stroke, as well as those that want the convenience and quietness of the 4-stroke. So resale prices are also similar.

Yes, some lakes have banned the older 2-strokes (that don't comply with 2006 EPA and CARB regulations), but that only affects you if you plan to operate on those few lakes. Similarly, EPA and CARB regulations for 2012 will be more stringent, but that will only affect motors that are manufactured after that date.

With prices so similar, cost isn't really an issue either. So it comes down to three factors:
1- weight,
2- operating expense, and
3- convenience/quietness.

The 2-stroke weighs less, but costs more to feed, and is noisier and smokier. The 4-stroke weighs a little more, but uses less gas (and no 2-stroke oil), and is quieter and makes almost no smoke.

In this size range, on this boat, for this number of hours per year, I would lean toward the 4-stroke. Then you can operate at any location for the foreseeable future. As a Nissan/Tohatsu dealer, I can tell you that the 25 and the 30 share the same block and have the same weight, so at 20% more power, the 30 is the logical choice -- since your boat will accept up to a 40. Make sure that you get the most appropriate propeller, depending on how heavily you will be loading the boat -- steeper pitch for lighter loads and higher speeds, lesser pitch for heavier loads and better control at lower speeds. But that is a discussion for the prop forum.

 

[Wee Hooker]

Re: 25 Hp 2 vs 4 stroke comparison?

Ok Gents, I'm convinced, I'm going 4 stroke this time around. Likely a 30 ( if I build a packae from scratch) becasue it's only $400 more than the 25. Still from what i'm reading, I get the impression that WOT speed will only be a MPH or two greater. Not sure what i'm gaining unless maybe it will be evident at "loaded down" conditions??

General question:
Is there a big difference in reliability /economy with carbed vs injected 4 strokes in this range??

 

[pvanv]

Re: 25 Hp 2 vs 4 stroke comparison?

Better atomization with fuel injection. Means better efficiency. Means better economy. The current Tohatsu/Nissan 25/30 is fuel injected.