2 stroke vs 4 stroke

[Ellis Rowe]

I have a Simmons Skiff with a 4 stroke Yamaha 25, which I haven't been entirely happy with. I recently built another Simmons for my daughter, and am trying to decide on a motor. Availibility is an issue here in Maine, and of course price. I can buy a 2 stroke Yamaha 25 installed for $2900. The same dealer has a 4 stroke Yamaha 30 installed for $5200. The performance would be about the same with either motor. The 4 stroke has power trim and tilt which would be nice, and is not available on the 2 stroke 25. I know that the 4 stroke pollutes less, and gives better fuel economy. But how much better fuel economy, and how much more environmentally friendly is the 4 stroke? Also, I seem to remember reading about an after market power trim and tilt. That would be part of the equation. Does anyone know where I might track down some information about these units? Any thoughts on the 4 vs 2 would be appreciated.

[S/V Laura Ellen]

If you plan on using the boat on inland lakes, I would spend the extra for the 4 cycle. Many areas are starting to restrict the use of 2 cycles.

[Woxbox]

And how about the noise factor? The 4-strokes are generally quieter, plus the noise they make tends to be at a less annoying frequency in my experience. The boost in fuel efficiency is significant - but you'd have to buy a heck of a lot of gas with the 2-stroke before you'd shelled out the extra cost of the 4-stroke. The other factor is reliability. In theory, the 2-stroke, being a much simpler engine, is more reliable but I don't know if that's been proven out on the water.

[warthog5]

a Simmons Skiff with a 4 stroke Yamaha 25, which I haven't been entirely happy with.

I alway's hear people complain about a 4 stroke's performance. When you finally get the imfo out of them [not you :)] you find they are talking about a Yamaha.

When you look real close at a Suzuki you will see the diffrence.

Lower gear ratio that the other 4 stroke's and it swing's a bigger prop.
This mean's more bite and better holeshot.

Plus you get a timming chain, unstead of a timming belt and most of the Suzuki's in the same HP as Yamaha have higher output alt. on them.

Gary at Lake & Sea in Maine is a great dealer. :)

[ccmanuals]

I would give serious consideration to the Evinrude E-Tec. Read about it here:
http://www.evinrude.com/en-US/About.Us/FAQ/E-TEC.htm#Q3

[Tom Robb]

I think I'd go with a brand who's local dealer I can trust to give the best service. They all make decent motors. Parts, service, standing by the product is a deal breaker/maker.
We seem to to get a lot of talk here like 4cycle is some new exotic untried technology. :rolleyes: Bulls...ony.
Chocolate, vanilla, strawberry... pick the flavor you like.

[pipefitter]

Had a customer come in and had just bought a new 4 stroke.Says,sure is quiet but his brother inlaw is one who yells when he talks normally and now that with the quieter motor,all he hears is BIL. The 2stroke used to buy him some time of p&q while underway atleast.

[Ellis Rowe]

ccmanuals; according to the information on the website the smallest ETEC is 40 HP and is a freshwater model. I need a 25 or 30 HP motor to be used exclusively in salt water. The ETEC'S aren't rated for salt water until 90 HP.

[erster]

I will make an attempt to cover this with general comments, and these may or may not apply to this thread, but something to keep in mind for anyone reading this post. When you look at how far the Simmons Sea Skiff has come from its original inception and intent, the boat is doing more than it was ever ask to do, when people begin to fine tune them with the issues of motors now. Most of the old style motors were pieces of heavy metal, loading the stern of the boat down, but rarely did I ever hear so many complaints about the particular design being squirrelly, wet, rolly,slower than expected, bow too high and sliding across the waters in turns as we are hearing about now.

Many of the 18 footers were promoted by seasoned folks as only using and getting by with the old style 25 hp. short shafts Evinrudes and proud of how they seem to go and go, and handle the inlets and the likes and were just good old simple boats for the novice. Each had a simple steering wheel, side mounted controls and a bailer, bench seats, and most people dealt with proper load postioning and that was it. The very first one that I can recall riding in had the really old style 28 hp that took almost three people to pick up.

Now we see the same boats with big and heavy built center consoles, even when they are built liteweight keeping in mind the structual necessity of them, cooler seating, fuel tanks that exceed six gallons, tackle boxes, big helm seats and on and on. The overall weight is displaced differently, too. We also see a lot wooden trim, which also adds weight to the sensitive in nature boats. We are also glassing the bottoms of these hulls, adding weight to them.



Now we wonder why this small bottomed hulls are weak on performance, now. Part of performance of any boat, is in the amount of running and undisturbed bottom of a particular hull. The 18 lacks a lot of planning surface in the existing beam, that a lot of folks are used in in today's modern era of small craft. Two to three degrees of increased angle on the well angles, either in new construction, or by adding a small wedge feature between the motor and well front, especially with the added feature of power trim or tilt goes a long ways to help the performance of the smaller hulls with diverse layouts. At the high end speeds, its critical to also trim the nose of these boats back up a bit, or they will have the tendancy to handle a bit scary until you get use the handling characteristics.

So in conclusion, whatever is placed on what I am assuming to be an 18, as you do speak about the 25 hp engine, or even a low sided 20, which in some of the hulls of that size and configuation, had the same beam to it, there is a lot to consider to what any brand of motor will do, and not really the fault of the engine, sometimes, for these hulls.

[High C]

Tohatsu makes fine little 4 strokers, also under the Nissan name. They offer both a 25 and a 30 on the same block, 3 cylinders and 150 lbs. Priced much lower than Yamaha, about like a 2 stroker.

And listen to the Erster....

[RodB]

I can vouch for the Tohatsu 4 strokes as being solid engines, my brother has the 25hp Tohatsu...If you can get one at the cost of a two stroke, then you wouldn't be dis-satisfied. Afterall, the four stroke engines do allow you to avoid mixing oil in the gasoline, which is a pain...

To continue...IMHO...

The outboard industry is changing as we speak, but there are still some very good quality two strokes around for very good prices...at least for now.

You have to look at the power you require and the weight of the outboard when powering smaller craft. I doubt you can justify the other choices over the quality two stroke if you consider the lower cost, lighter weight, and very good performance. A good friend of mine, who just recently bought a $30K Maverick flats skiff powered her with a Yamaha 90 two stroke...and didn't consider a four stroke at all due to weight. Of all motors considered, the lighter, two stroke rose to the top of the list simply due to quality in performance and least weight. I realize the lower horsepower engines have less weight variation/differences so the choice for you might hinge on whether the two stroke has an oil injector or not, and is it more powerful, mixing oil in the gas, etc.

For my flats skiff, I chose a 90hp Yamaha 2 stroke because there was no comparison when you looked at weight compared to power. No one that I met in the industry suggested a four stroke. They said, "Get a two stroke while they still last or you'll be spending lots of money for the new four strokes".

My two stroke Yamaha motor weights 267 lbs. The 4 stroke I think about 360 or so(this may be incorrect but I know its significantly more). That lessened weight makes a lot of difference in the performance in my 18 foot 800 lb hull weight skiff and I wouldn't even consider a 360 lb motor. I would have to think hard about considering a 115hp two stroke model, which would probably be worth the change due to more horsepower...but also costs another $3K and weights 360 lbs.

Another thing, its very hard to beat a two stroke Yamaha motor period. Compared to any of the competition you cannot choose a better motor unless the ETEC is totally right about all their claims...and if you don't mind spending a lot more money...and they ain't as light as the older model two strokes. If I hadn't found the Yamaha I did, I would have settled for the 90hp Tohatsu (Nissan is the same) which is very hard to beat in performance for the dollar, just a bit heavier than my Yamaha. All in all I think that Yamaha and Tohatsu are fairly similar in quality and would be my choices. The knowledgable folks I know in the industry tell me the jury is still out on the Etec for now, but who knows, they may end up being the best motors ever. From what I have seen and been told ...Yamaha and Tohatsu are used predominantly on our Texas coast simply due to solid service in the rough salt water enviornment. From my personal research...service folks in the industry pretty much recommended across the board... Yamaha or Tohatsu... above the others. The Etec is going to change the industry if they can live up to all their claims...but that remains to be seen and they ain't cheap or all that light in weight.

If you can power said boat with a 2 stroke Yamaha...can you save thousands over the 4 stroke and the Etec? I doubt anyone can justify spending extra money for the 4 stroke. For the consumer, I think the 4 strokes need maintenance, are too heavy, cost too much, and offer less in the hole shot.

Decent care of a quality two stroke results in good consistent performance over time. ..just run her often enough, after use in salt water wash her down both inside (water pump system) and out...spray the head et al under the cowling with WD-40 after a warm fresh water rinse and drying out. . . spray all outside fittings and metal joints, etc with WD-40 too... spray electrical connections with Corrosion X or WD-40...If you perform this basic maintenance the heads of your motor will look "as new" even after several years use. Any bolts or nuts can be removed and coated with a gasket adhesive or waterproof lubricant to keep them from ever seizing up with salt water use.

You could also go slightly larger in motor horsepower in a two stroke model and the weight will be reasonable to a point...just be realistic on how much horsepower you really need.

I have read (in some publications) of those in a business running outboard motors every day doing significantly better in over all operating costs for the year using 4 stroke outboards. This could be the gospel truth...or not... I realize lots of the 4 stroke hype is true...but I think for me, or ...for most of us in the real world, a quality two stroke outboard offers plenty of performance and longevity for a lower cost with the amount of use an average boater requires. If a Tohatsu 4 stroke is close to the price of a Yamaha two stroke, I would want to run both for a comparison before deciding, but I would begin slanting towards the Yamaha two stroke.

To answer your questions specifically, I would think the 2 stroke 25hp with an aftermarket tilt and trim would work fine. I have seen this setup and it works just like the built in units....and I'm assuming would still be cheaper than the 4 stroke.

You asked for opinions and suggestions.

Good luck,

RB

[Ellis Rowe]

Erster, Just to answer your comments. The boat that I'm powering is the boat that I built for the WB how to article. Although there is a small console and 11 1/2 gallon fuel tank this boat is lighter than an original Simmons. I have stated in the past that these boats get squirelly when overpowered, and I'll stand by that opinion. Which is why I recommend a maximum 30 HP. I have a lot of experience with these boats, and choose to put my daughter in one. They aren't the ultimate boat for all purposes, but they do what they do very well. Handle rough water and run difficult inlets safely.
Now, about those aftermarket trim and tilt units. Does anyone know a source?

[erster]

Performance was your number one issue in your original post. As stated, one single issue, weight and its distribution, plays a key role in the single issue of performance in that boat. My original post addressed this in general terms as your conditions and particular boat was not stated in the original posting.

If I recall correctly, but cannot really remember, the 25 maunal tilt engine requires a different engine mounting bracket completely to accomadate the power trim and tilt. This is also an added cost to the engine for your change out, along with added weight. Are you actually better off with the 2 stroke engine on that boat for performance, and related issues, versus the 30 hp four stroke?

I can't answer that, as each individual looks at power boats and the issue of adding oil differently and the smell and dumping of oil in our ever increasing dwindling estuaries. The quietness of the four strokes sells me as the second feature and would never turn back, and deal with any performance concerns or lack of, especially if this was my own personal kid. FWIW, my own son owned his first boat with a 9 hp on it, in the beginning, even when he had numerous hours of seatime while even in diapers with me, for the issue of the learning curve on his own, and preformance was not in the equation. Again this may not be an issue or relavent in this case.

I would personally consider the power trim and tilt issue as the number one issue in the choice of an engine but not really sure of the net costs amount in this complete changout, and you are also limited with that boat's ability to trim it manually. Tohatsu has millions of hours of time in the commercial fishing fleet on the bays of the Chesepeake Bay, alone.

I hope this clears up any misconceptions left in my earlier posting.

If you want to save any more money on a two stroke, this link sells engines with a high success rate of quality used or rebuilt engines, and comes with a warranty. They also sell parts for all engines, too with great service.

http://www.boatmotors.com/rebuilt_outboard_motors/

[erster]

Let me address something that folks are not finding out now, until its too late with the two and four stroke issues. In the new formulated gas products with ethanol introduced in certain areas, and the issue that a lot of trailable boats that are fueling up at road side stations, are find out, The gas-oil blends are seperating from the oil blended in the gas tanks, after sitting in some of the larger tanks, and causing harm for the engines that require the blends to lubricate them.

The snot that is also being generated with the ethanol products, and water related issues, are also plugging up the fuel water seperators causing many to be stranded on the water. There are some serious issues also with certain fuel tanks in flberglass and even some of the plastic tanks, causing the linings to disentergrate, or even some ruptures to take place, dumping gas in the bilges of the boats.

[Ellis Rowe]

Being somewhat of a tree hugger I've decided to stick with a 4 stroke. I really like the idea of the Nissan/Tohatsu as it is fuel injected in the 25 and 30 HP models. In my research so far however, I've found the price to be pretty close to the other four strokes, and nowhere near the two strokes. The power trim and tilt is very important to me also, and I'm afraid the aftermarket unit would be a hassle.
Erster, not to beat a dead horse, but my original post said nothing about how important performance was to me. The only reference to performance was that the 2 stroke 25 and the 4 stroke 30 would have similar performance.
My only beef with this forum is that from time to time the original question is more or less ignored, and the post goes to different agendas. That being said, thanks to all for your comments, and wish me luck in finding a motor up here in the hinterland.

[erster]

I have a Simmons Skiff with a 4 stroke Yamaha 25, which I haven't been entirely happy with. The performance would be about the same with either motor.

In a forum setting, this comment leaves a lot unspoken. I may have missed something in the translation, but when you spoke about alternative engines, in almost all cases, speed and plane comes to mind, as I did not give any consideration to any severe motor problems.


Is it the actual engine, the actual getting on plane, speed of the package, the actual fuel consumption for such a small hp engine, its all up for interpretation, indeed. Most mechaincs speak about the reserve power or actual guts with the four strokes, indeed.

If one single issue comes to my mind of the two, past the clean burn and the quietness of them, personally I lean towards fuel consumption in discussing the two different engines.
FWIW, I have a 40 hp Suzuki, four stroke, that I run with a six gallon fuel tank since 1994, and makes an average 25 mph. and run to the barrier islands, about thirty miles round trip, with three of us on board , and as of the last trip have been really pressed to burn four gallons of gas with the boat. As far as continuous duty, the engine is six years old, and I have spent only service money on the engine, which amounts to about 400 bucks in that time frame.

[Ellis Rowe]

Perhaps I should have made my problems with the 4 stroke Yamaha more clear. Despite a separate Racor filter and close attention to fuel supply the carburetors have been a pain. I bought the motor brand new from Jeff's Marine in Thomaston Maine, and have had nothing but grief from him. When the motor is running well, the performance is fine, although not as fast as my old 1979 25HP Johnson. The Johnson would top out at 32 mph on the gps, and the Yamaha at 28 or 29. I wasn't concerned with the loss of speed, but somewhat confused. Every outboard mechanic that I talked to prior to purchasing the Yamaha stated that it would be faster than the Johnson. There reasoning was that in the old Johnson the HP was measured at the powerhead, and with the Yamaha it was measured at the prop. Sounded reasonable to me coming from several professionals. We tried five different props with the Yamaha using a portable tach and got the best speed available. It's a 9 7/8" 13 pitch. I have no idea what was on my old Johnson. Anyhow, anything around 30 mph is ok by me.

[erster]

FWIW, Good read. Just google
"fuel additive for gas boat tanks" I am not sure of the name of the product that I think West Marine is selling for gas tanks, not the stabil stuff, to add to the gas, but it may be of some help for you. I would seriously consider doing away with the large fuel tank. With most all four strokes, its pretty darn hard to burn six gallons a day in a boat of the weight and size.

Second , ethanol will clean out the dirt in tanks, clogging fuel filters, so boaters should carry spare filters.
BoatUS's Fort also warned that boaters should not leave gasoline unused in their tanks for months at a time. It could attract condensation with New England's dramatic temperature changes, and the water can mix with ethanol and enter the tank, making the new blend a potential problem during the winter when owners leave their boats untouched for months.
Boatyards, especially those that service older models, have seen minor cleaning issues so far this summer. FL Tripp & Sons Inc. in Westport Point has serviced 50 or 60 boats with clogged filters and dirty carburetors.


http://www.boston.com/business/articles/2006/07/15/boat_owners_grapple_with_new_blended_fuel/


http://www.mvtimes.com/news/2006/07/13/ethanol_additive.php

[Stinkbug]

Best gas additive is called Seafoam

[Stinkbug]

http://www.scooterworks.com/images/Product_Images/std/seafoam.jpg

[Dave Fleming]

When the hell are you going to grow up?:mad:

[Stinkbug]

When the hell are you going to grow up?:mad:

Wassa matter big boy? Not enough fiber in your cereal these days?:eek:

[Thomas Williamson]

Hi Elliis,

Just my 2 cents worth. I originally planned to put a 4 -stroke 30 on my Simmons. It turned out that the Yamaha 4-stroke 30 was the same exact motor as the 40 with a different head. This meant that they were essentially theh same size and weight so I went ahead and got the 40 since I was not adding any more weight or width for a little more power.

This motor works OK on the Simmons. I am a very conservative boat operator and I do not feel that the boat is really overpowered with the 40 (i.e. you do not have to drive around at WOT). However, I do feel that it is a bit too much weight in the aft end of the boat. If I had to do it all over again, I would go with a 2-stroke 25.

The motor is a 2004 model with <100 hrs on it and is in very good shape. It has been meticulously maintained. I feel strongly enough about this that I would be willing to trade someone even for a 25 or 30hp 2 stroke in similar condition.

Thomas

[Lew Barrett]

Just a bit more fuel for the fire. Here is another post on the subject with a couple of my favorite authorities citing their opinions:D

http://www.woodenboatvb.com/www/vbulletin/upload/showthread.php?t=49341&highlight=stroke+outboards

For a really comprehensive and authoritative discussion of the latest developments in 2 stroke technology, including a mention of Evinrude's approach, (from one of the best ever technical writers, Kevin Cameron), try to pick up a copy of last month's (not this month's) Cycle World. Kevin's article covers it all, including technical differences, whys and wherefores, as well as some prognostication.

Lew

[Paul Pless]

from one of the best ever technical writers, Kevin Cameron

You got that right, and completely entertaining to.

[Lew Barrett]

I love him, metaphorically speaking.
Lew



You got that right, and completely entertaining to.

[Tom Robb]

I had to race against one of Kevin Camron's bikes once. Once was plenty. The man knows his stuff, and a damn nice guy to boot.

[RodB]

For what its worth, I looked at performance with outboard jets, and researched outboards with jet performance for the least weight in mind. Outboard jets cause a loss of power by at least 25% in a motor compared to using the same motor with a prop...so the performance of the motor is really tested when you replace the lower unit with a jet pump.

The Jet pump dealer here in Texas has experience over many years using every make of outboard motor and many of the two strokes that have been around for a long time perform very well...mid-size to smaller two strokes from companies like Yamaha, Tohatsu, Johnson and Evinrude (Bombadier?), Mercury, etc. I don't think jets are made for any motor smaller than 40hp. From what I can gather...the overall view is that jets powered by four stroke outboards "SUCK". The words I heard quite a bit were "they're a dog"...four stroke jet pump outboards are lame compared to the same setup with a two stroke.

We are looking at the smaller motors here... I think one of the best we ever owned was a 30hp two stroke Johnson. . . ran like a top and never lets us down. ..very easy to maintain...not quite as simple to gas up as a four stroke, but an awful easy engine to use and maintain. The really nice thing about a quality two stroke is that you get a lot of power in a small package.

Maybe it comes to this...if you need reasonable power and don't want to deal with oil mixed in the gas, like the quietness of the 4 stroke, don't mind the weight, and the cost of the motor over the time you will probably own it...won't affect you that much, then the choice of a 4 stroke is the one. If you want max power and accelleration for minimum weight, and don't mind mixing oil in the gas (my 90hp has an oil pump), then choose the two stroke.

I have seen one really good version of an after market tilt and trim for smaller motors... and it was certainly equal to any manufacturer equipment I have seen. I wouldn't rule it out until you checked it out for cost and ease of installation.

RB

[Ellis Rowe]

RodB My next question would be, Who is the manufacturer of the aftermarket tilt and trim? I havent't been able to find anything on line. Of course, I'm an analog person in a digital world.

[RodB]

You know, its been such a long time that I will have to do some checking. I know a small boat builder in Tampa had a line on them and they worked perfectly on 25hp outboards. I think they were appropriate for motors up to 150hp. You could start with Bobs Machine Shop, they may make one or know who does. They specialize in hydraulic jack plates.

RB

[Ellis Rowe]

Rob, I found them on line made by CLC. The smaller unit which will carry up to 35 HP is around $400. The only problem that I see is that they space the motor 5 1/2" aft of the well.

[RodB]

Could you compensate in the motor well for the additional 5-6 Inches?

Some more interesting info:

If you buy a mid sized 4 stroke outboard...and at the same time the same horsepower motor that is an Etec two stroke...you will spend several hundreds of dollars doing the maintenance (oil changes, adjustments) on the 4 stroke in the first three years...while the Etec will cost you nothing except for changing out the lower unit oil.

RB

[Ellis Rowe]

Rod, The boat is already built, so altering the motor well would be a job, not to mention the loss of 5 1/2" in the boat. I had checked out the etecs, but according to their website 40HP is the smallest currently being built and it is rated for freshwater. The smallest saltwater rated etec is 90 HP. This boat will be used exclusively in salt water.
Erster, This boat has an integral 11 1/2 gallon Tempo fuel tank. However, an 11 1/2 gallon tank is also a 6 gallon tank if you only put 6 gallons in it. I just like the option of having the extra capacity if needed.
As stated previously, availability is an issue here in Maine.
Warthog, thanks for the tip on Gary at lake and sea. He has a 30HP Nissan four stroke which is what I've decided on. They seem to be the only 25 or 30HP's with electronic fuel injection. Yamaha's and Suzuki's are carbuerated until 40HP.
Anyhow, thanks to all of you for your input.
Look for an article in WB on rigging and sea trials.
Thanks again, Ellis