2 stroke VS 4 stroke

[bassyac]

I view this forum all the time, just to see all the issues with these engines. I have a 2014 DF300, not my first Suzuki, but my first 4 stroke. I was able to run the 2 strokes all day at WOT without any fears. Someone on THT forum said this engine is like a car engine. I had an I/O and would not run it past 4300 rpms. This engine I can get up to 6350 rpms at WOT. Right now I run 4000 most of the day and run it up to 5800 rpms for about 30 sec. everyday just before I pull into the dock. I see guys fly by me many times and just-wonder, lifetime issues at that rpm. What is right?? Can they run at WOT or should I keep it under 4500 rpms, not worried about fuel.
Thank you
John

[Solarman]

Granted 4 strokes are very reliable running on the highways with antifreeze cooling systems keeping the motor temps down, and they're very strong competition for 2 strokes on the waterways. But running saltwater through them for cooling is asking for trouble, and very high dollar repair costs. The weight factor, dollar cost factor, complexity of mechanics, mixed with saltwater environment just means that scrap yards will be a great investment in the future. Ha ha.

The 2 strokes have proven themselves for over 40 years. Much lighter in bulk weight, easier and less costly in maintenance/ repairs, could even excel much farther in the future, especially with fuel and oil injection systems. Getting away from carbs was such a big advancement, not to mention the electronic ignition systems. Although carbs and the older ignition systems kept the dealerships in profitable repairs. The electronic ignition system, Fuel, and oil injection systems eliminated so many repairs, that dealerships were losing serious profits. Along comes the 4 strokes, forget the 2 strokes, dealerships are back into making huge profits in repairs.

Manufacturers basically have dropped 2 strokes because of their simplicity and efficiency, because the 4 strokes, with so many more moving parts, and complexities, will keep them making the major dollars, both in sales and ultimately, the repairs.

Good luck you 4 strokers, it's like adding a fourth strike in baseball, or a fourth out. It only prolongs the inevitable, but this allows more money to flow out of your pockets throughout the game, going to all those that produce and sell it.

[bassyac]

Thank you for that response,however I have one(4stroke) and can not change. I am looking for RPMS and their issues because this is my first 4 stroke. My old Suzuki 1986 150 is still on the water. In 5years I may sell anyway, with a year left on warranty. You know all the problems I have already had, next boat and engine is going to used. Just a note, that I am not a 2stroke hater nor am I a 4stroke hater, Just would like to know how high do 4 strokes RPM run,for running all day.
Thank you
John

[Harper]

As to choices, 2 vs 4 stroke, to each his own, I say.

I disagree, however with the opinion you cite from THT. There's a lot of very opinionated jerks on THT who'll tell you this boat or that boat, this motor or that aren't worth a tinker's damn, and they've no qualms at all about telling you how stupid you are to disagree. I don't think the 4 stoke marine engines of today are meant to be run like automobile engines. In fact, if you run them that way, I think you're more likely to rum into trouble than if you run them like outboards have always been run. I wouldn't treat them any differently than I would a two stroke. I know others may disagree, but I'm not going to call them stupid or ignorant. It's just my opinion, and they will have theirs. Do your maintenance properly and often, get to know your equipment, listen to it and do your best to catch any potential problems early, while they're still minor.

[Solarman]

Excuse me John, I meant to add that both motors ( 2 strokes I know of, 4 strokes, according to this forum) seem to run very well at their rated RPMs. most older two strokes run well at 5k - 5.5k , while I hear the 4 strokes do their best running at 6k, and both motors do use more fuel at the higher RPMs, they are built to run these RPMs. I run my 2 strokes 4800 - 5000 RPMs going 40 - 60 miles off shore then troll 8 - 10 hours, and run back to port the same speeds. And generally seas are 1 to 3 feet going out, and 2 to 3 foot coming in.

They won't last forever, but they will fall apart sooner if not used.

Enjoy your boat, let it breath. Happy boating.

[Moonlighter]

Ok, I will throw my 20c worth in too.

Modern 4 strokes are fine to run at high revs for as long as you would run a similar HP 2 stroke. They are designed to do it. Plus, they will troll all day at idle speed or whatever, and they won't foul up, overheat or carry on like the older 2 strokes do.

Plus, they use half the fuel over a days fishing. Sometimes even less. Troll for 6 hours with a 140 2 stroke and then with a 140 4 stroke and you will see a huge difference. Join the rest of the world where we are paying the equivalent of up to US$5 per gallon of unleaded and this factor alone will soon get your attention!

When I have said that you need to prop your 4 stroke Suzuki to hit 6000rpm, that doesn't mean I am advocating running them at those revs all the time. It means that you need to get the overall gearing right for optimum performance and engine life. They are a bit harder to prop right than a 2 stroke but it's not that hard.

Plus, it's not very often that you can run at WOT speeds anyway, the boat and engine might cope, but hell, the crew won't!

Mostly I sit my DF115 on comfortable speeds and revs of between 4-5000rpm. In my mates Striper, 4000 to 4500rpm gets us really moving at about 25-30knots so unless it's almost glassy, we don't bother going harder than that.

But having said all that, the DF 300 on his Striper is a beast!

Man, at 6000rpm that thing sounds like you've got a Cosworth F1 engine on the back! Sweeeeeet!

My local dealer supplies and services engines for local volunteer marine rescue groups who do many hundreds of hours per year including towing boats, and he also supplies pro fishemen. They regularly get 4-5000 hours up before they change engines, and their engines then get snapped up by savvy recreational fishers. He did one changeover recently where a pro fisher's DF140 had 8000 hours on it. Suzuki bought this motor back from him, and stripped it down to see just what they would find. Still in perfectly good condition inside.

If you like:

Smooth power delivery
Quiet running and almost dead quiet at low revs
No smoke
No adding oil to fuel or oil tanks
Ability to lug extra loads without losing much speed
Similar servicing costs to a 2 stroke in reality - I can compare costs of servicing my DF115 with my previous Tohatsu TLDI and Yamaha 70 and frankly, it's not a hell of a lot different.

The 4 strokes are just nicer to live with overall

Go with a 4 stroke and there will be no chance you will go backwards to a 2 stroke.

The reason that 2 strokes are dying out is because they can't meet modern pollution standards. Simple as that.

Kinda like the dinosaurs...... Couldn't adapt to new environmental conditions!

[dubrus]

we pay well over 8 dollars for 1 gallon in the UK. I'm sure people in other parts of EU pay even more.

Think yourselves lucky elsewhere that running big engines is "affordable" when 5 bucks is a pipe dream here.

Cheers

[Harper]

I won't tell you what we pay here in Texas, USA, but I also don't care to get into what trouble this "land of the free" is in, financially and every other way. But hey, I guess the whole planet is goin' down the tubes. That's why I go fishin'.

Back on topic, I cruise around 3500-4000 most of the time, in a 20' center console medium-deep V hull with T-top. It's between 25 and 30 mph at that RPM, a comfortable cruise speed. Heading out to the oil rigs, I can't usually run on plane, since the seas run almost constantly at 2-4' minimum in this part of the gulf coast

[Moonlighter]

Mike, I couldn't agree more.

To Bassyac - I wouldn't worry about the young dudes blasting past you when you are cruising comfortably along. Their engines, and their bodies, will handle it just fine

Meanwhile the rest of us just get on with enjoying our boating. For us, I doubt if we could wear out one of these motors, more likely, time and exposure to the salt water environment will be the limiting factor far more than wear!

And on that topic - I will say one word - ANODES!!!!

If there is one service item you pay attention to at least annually, it is the external and more importantly, the internal engine anodes.

My Zuke guy here was saying to me recently that the number of used boat imports from the U.S. where there were significant corrosion issues inside the Suzuki engines he sees was far out of time with what we see with Aussie bought and serviced engines. His view was that the U.S. purchased motors rarely seem to have had their internal anodes inspected and changed on a regular basis. Maybe it's something people aren't used to doing, but it is the most vital thing for long engine life!

I do note that it seems that our U.S. cousins seem to do a lot more of their own servicing, while the vast majority here get servicing of the engines done by the dealer.

When you think about it, most of the people posting on this forum do so because they have an issue or problem that they want help with. And when you consider really how few people, in the context of this being an international forum, actually post here, it says that the vast majority of people never have a significant issue with their Suzuki outboards, whether 2 stroke or 4 stroke.

In fact, even on this forum, if you subtracted the percentage of threads where the problem experienced was not in fact a Suzuki fault but was :

1. a problem with the boat, be that fuel or electrical systems
2. A problem with the installation, or operation!
3. Simply a mismatch between boat and motor
4. People wanting to add the latest technology (ie N2K gear) and seeking advice,
5. Normal wear and tear issues.......

Then the number of genuine, real, Suzuki problems or failures is really quite low in the scheme of the volumes of these engines in the market.

Effectively, all we see on this forum is the complaints! We never hear from the probably 99% who are happy, do we? So you have to keep that in perspective too.

[38 Angler]

Go with a 4 stroke and there will be no chance you will go backwards to a 2 stroke.

The reason that 2 strokes are dying out is because they can't meet modern pollution standards. Simple as that.

Kinda like the dinosaurs...... Couldn't adapt to new environmental conditions!

************************************************** ************** I don't claim to be a ''know-all'' but having been a mechanic for many years leads me to believe that I am some-what ''initiated'' . --- It is my contention that a modern 2-stroke , an E-Tech for example , is in no way inferior to any 4-stroke . As far as consumption , pollution or power-delivery is concerned they seem to exceed (in a positive way) todays 4-strokes . Maintainance-wise they are much easier to live with . --- NO , I don't own an E-Tech but would like to .

[bassyac]

Ralph/Mike/Grant
Thank you all
I have had some problems in the past, that were not my fault and I did not want to create problems. The dealer is able to see how many and how long I run this engine at all RPMS.HE said I should run WOT as much as I want, I run WOT 30seconds or so every time I am out.
I did do a search on the THT forum, That gets out of hand with responses, I like the strait forward responses here.
Grant You are so right WOT is not for me, I go along at 28 knots is fine.
Ralph 60 hours,so far this season, knock on wood, Everything is running GREAT. Running offshore Saturday 50 mile round trip.
Mike I do the same, My ocean off Long Island,NY run 3-5 ft most of the time with 7 seconds, 28 knots is OK by me
I wish to thank you all, catch what you want, Good luck
John