# outboards: 2 stoke or 4 stroke



## oldironnut (Feb 28, 2010)

I am going to buy a new outboard motor in the 5hp to 10hp range for a trailor sailor. I have heard that laying a 4 stoke on its side will cause oil to go places inside the engine that it shoudn't go. Since I am going haul it sometimes in the pickup or inside the boat is this something I need to consider? I've had motorcycles and lawn mowers up side down and when I start them they are sometime hard to start and smoke like crazy until the oil burns off. I would rather not do this if getting a 2 stroke engine would be better. I like the idea a 4 stroke-quiet, no oil to mix etc. And I wonder if the modern 2 strokes would be as nice to operate. Or am I worrying about nothing. Also with purchase price of a few hundred to over $3000. I want to get my money's worth.


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## FSMike (Jan 15, 2010)

Some outboards should only be laid down on one particular side. The mfgs label them accordingly and explain it in their manuals. No biggy, just don't forget which side stays up.


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## sailingdog (Mar 19, 2006)

Actually, you can lay almost all of the four-strokes down on a particular side. They're a lot quieter than most two-strokes and more fuel efficient as well. Finding two-strokes is getting more difficult, and carrying one means you have to carry two consumable components for fuel, rather than just one.


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## tager (Nov 21, 2008)

I would get the 4 stroke. 2 strokes are just run so dirty that I know it is upsets the marine environment. Have you ever ran a 2-stroke in a bucket?


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## Bellita (Jul 9, 2009)

I have a Tohatsu 3.5 hp four stroke engine that I store and transport horizontally. you must lay it down on the side opposite the throttle side. if you do that, it starts on the first or second pull consistently. one time I did not do that and oil did seep into the cylinder. Fastest way to clear it out was clean off the plug, use one squirt of starting liquid into the carb and it started fine and burned off the extra oil. The engine runs great and is much cleaner to run than my other engine, which is a two stroke ( that now sits unused in my garage). Get the four stroke. slightly heavier than comparable powered two stroke, but the difference is slight at the horsepower you are describing and it is much easier to use/maintain/keep clean.
I can also say I'd buy another Tohatsu. It's been a really super little motor.
Good luck with whatever you decide to purchase.


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## MarkCK (Jan 4, 2009)

I agree with going with the 4 stroke. I dont know about new 2 strokes but the older ones seem to have trouble with ethanol. This probably varies by year and manufacturer though (or maybe its just my motor). I have a 25 year old 2 stroke that I am going to replace with a four stroke this spring.


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## sailingdog (Mar 19, 2006)

I had the 3.5 Tohatsu and would second buying it again. Only reason I don't have it still is my friend bought it for his trip to the Bahamas.


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## chef2sail (Nov 27, 2007)

We have the 4 hp 4stroke Tahatsu. It runs like a charm, is quiet, easy to manage. One thing to look at is the internal tank enough to meet your needs. My wife and I like to anchor and sometimes take a 1-2 hr dingy ride up some of the shallower parts of the Chesapeake rivers/ coves we cannot take the boat up. Most 4 hp do not have a choice or internal/ or external tank and all 4 stroke below 4 hp are internal only. This particular Tahatsu has either use of an internal or external tank and we usually use the external. The three gallon Moeller plastic tank straps down nicely on the floor of our walker bay and stays in the dinghy all the time, even when its in its davits. This keeps us from keeping a can of gas aboard the boat to refill the engine which is a safety factor for me also. (Tahatsu and Nissan are the same engine. usually the Nissan is a little more expensive)

Dave


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## kwaltersmi (Aug 14, 2006)

We have a 4-stroke Honda 2hp for the dink and love it. It runs clean and quiet with really impressive fuel efficiency. As others have mentioned, you can only lay it down horizontally on one side, or oil will leak. However, the Honda 2hp has resting pads built into one side of the cowling so it's easy to remember which side to set it down on. It's also air cooled so we don't have worries about water pumps, thermostats and silty water causing problems. The exhaust is still underwater so the noise isn't loud like on many other air cooled outboards/weedwackers.


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## sck5 (Aug 20, 2007)

I have a 2 stroke mercury 8hp that I have had for a long time and it still works great. Very hard to mess up that motor and very easy to do maintenance. 4 strokes are more complicated machines. But by far the biggest plus of a 2 stroke is that they are way lighter for a given horse power than 4 strokes are.


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## AdamLein (Nov 6, 2007)

sck5 said:


> I have a 2 stroke mercury 8hp that I have had for a long time and it still works great. Very hard to mess up that motor and very easy to do maintenance. 4 strokes are more complicated machines. But by far the biggest plus of a 2 stroke is that they are way lighter for a given horse power than 4 strokes are.


I have had one of each; my 2-stroke is 20 years old and still runs quite well. In addition to weight the related advantage is size: my 2-stroke is the only motor over 4hp that I can fit in the annoying transom hole on my C27, and still have it tilt out of the water. But if I get around to glassing over that hole some day, I will replace it with a 4-stroke.


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## southshoreS24 (Aug 31, 2009)

tohatsu and Mercury small 4stroke engines are basically the same. the are even built in the same plant. the only main difference is the throttle is on the handle on a mercury and on the side on the tohatsu. I have a 5hp tohatsu and its great! a little strange to hear at low idle with only one cylinder, you keep thinking its going to die but that's just because its a 4 stroke. super quiet and runs like a champ.


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## sailingdog (Mar 19, 2006)

Actually, the small (<10 HP) outboards by Mercury, Nissan and Tohatsu are all made by Tohatsu. Also, the throttle on the tohatsu is the handle, just like on the Mercury or Nissan.... I don't know WTH Southshore is talking about.



southshoreS24 said:


> tohatsu and Mercury small 4stroke engines are basically the same. the are even built in the same plant. the only main difference is the throttle is on the handle on a mercury and on the side on the tohatsu. I have a 5hp tohatsu and its great! a little strange to hear at low idle with only one cylinder, you keep thinking its going to die but that's just because its a 4 stroke. super quiet and runs like a champ.


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## 2Gringos (Jan 4, 2008)

four strokes are pure marketing hype. They have one advantage over 2 strokes, and that is because they are quieter. they are quieter because they are only firing half as many times as a 2 stroke.

2 strokes have an advantage in weight, initial cost, maintenance, parts cost, and simplicity.

As for "two combustibles on board" Four strokes need two combustibles, too. oil is oil. 10w-40 burns just about as good as 2 stroke oil.

As for a slight fuel efficiency gain...take the added cost of the initial purchase, the added cost of maintenance, the added costs of replacement parts and spares, and total that up. Then see how many gallons of fuel you can buy for that. 

Then look at how much longer you can run a two stroke for the same money you spent on the heavier four stroke.

and if the marketing people at the outboard companies can figure out a way to make you think inverted three cylinder doo dads with a reverse thrust anti-cavitation widget is better than the four strokes they sold you last.....A bunch of people would all go buy those, too, and swear up and down how superior the new motors are and how smart THEY were to buy them.


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## MARC2012 (Mar 17, 2008)

Yamaha 4hp have internal external tank hookup.They are heavy though.marc


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## Lostmt (Jun 4, 2006)

I've got a 8 hp 2 stroke Suzuki and hate the darn thing. It's hard to start, drinks fuel like a drunk, can't carry on a conversation because of the noise, can't get the part I need to lock the throttle. Buy the gas @ $2.69 per gallon then add another $5.00 for the oil now you are close to $3.69 per gallon. I could go on and on about the darn sorry piece of crap.

If I can find some other dummy to take mine off my hands I'll get a 4 stroke.


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## svHyLyte (Nov 13, 2008)

The 2 verses 4-stroke debate will be influenced based upon one's intended cruising ground. In the Bahamas, much of the Caribbean and Central America, it can be difficult to find someone qualified to work on 4-stroke motors and parts may prove difficult to obtain, while 2-strokes are ubiquitous and easily repaired and serviced. For the last several years the 2-stroke motors really are no louder than their 4-stroke cousins, about as fuel efficient and certainly more powerful for a given size. We have several friends that switched to 4-stroke motors and all save one were disappointed with the results. On the other hand, we bought a 2-stroke Mercury 15hp new from West Marine several years ago that has proven completely unreliable, having spent more time at the local Mercury dealer than on the back of our dinghy. Fortunately we bought the 5 year extended warranty ($180 at the time) but that is coming to an end... Oh how I regret having given up our 1962 Evenrude Angler. It started every time no matter how much abuse to suffered and purred away faithfully. It's only drawback was it's weight (64 Lbs) for the horse power. Getting more horses for the same weight was a good argument but has proven chimerical.

N'any case, FWIW...


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## sailingdog (Mar 19, 2006)

Lostmt said:


> I've got a 8 hp 2 stroke Suzuki and hate the darn thing. It's hard to start, drinks fuel like a drunk, can't carry on a conversation because of the noise, can't get the part I need to lock the throttle. Buy the gas @ $2.69 per gallon then add another $5.00 for the oil now you are close to $3.69 per gallon. I could go on and on about the darn sorry piece of crap.
> 
> If I can find some other dummy to take mine off my hands I'll get a 4 stroke.


Ask 2Gringos...he seems to like two-stroke outboards...


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## mstern (May 26, 2002)

Some very practical observations above here, but your choices are this: new or used four stroke or used two stroke. You may get lucky and find a dealer that has unsold new two strokes in their inventory, but no one makes new two strokes at that size anymore. I ran into an outboard dealer at a boat show recently, and he was patting himself on the back that a couple of years ago, he bought several dozen small (<15 hp) Mercury two strokes in the last year they made them. He says they sell for more than their list price now. Unfortunately, you will be looking for an even rarer bird: the small two stroke long shaft. 

If you go with a used two stroke, I have had nothing but good experience with my 8 hp Nissan two stroke. Starts with the first or second jolt (I have electric start) every time, and is very good on gas. It also tolerates "old" fuel very well. I have used stablized fuel that is up to a year old with no problems.

If you do go with the four stroke, make sure the mounting bracket on your transom is rated to handle it. Older brackets have weight ratings, but the four stroke engines generate more torque than their two stroke cousins, putting more stress on the bracket. There have been a lot of threads on this site with this discussion about weight vs. torque capacities of outboard brackets; you might want to review them. I don't feel qualified to estimate if its ok to mount a 80 lb four stroke engine on a bracket that is designed to handle a two stroke engine weighing up to 120 lbs. Others on this site have expressed their learned opinions.


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## southshoreS24 (Aug 31, 2009)

sailingdog said:


> Actually, the small (<10 HP) outboards by Mercury, Nissan and Tohatsu are all made by Tohatsu. Also, the throttle on the tohatsu is the handle, just like on the Mercury or Nissan.... I don't know WTH Southshore is talking about.


oops, my mistake, the throttle is on the tiller but I meant to say that the shift is not on the tohatsu.


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## Cruisingdad (Jul 21, 2006)

I currently own two engines (three, if you count dad's).

I own right now a 6 hp 4-stroke mercury (circa 2006) and a brand new 2-stroke 15hp Yamaha.

I was ready to beg, borrow, or steal to get the 2-stroke. It was the last of 4 in SW Florida. Yamaha quit production on them this last summer in favor of the 4 stroke. That is too bad.

I believe the negative comments on teh 2 versus 4 strokes are true on the older 2 strokes. But many of the newer ones (all I was told but I have not researched it) are at least as emmission clean as their 4 stroke cousins and quite good with the fuel. Also, for those worried about having to carry two types of fuel, my Yamaha mix rate is 1:100 (yes, you read right... 100). Going to take a really long time to go through a quart of that mix and you can buy it at Sams or whever for $18 for a gallon!! I couldn't burn that much.

The 4-stroke technology for sailboaters sucks. They are heavy and typically harder to start than their 2 stroke cousins. I believe they are likely a bit more efficient, but do we motor enough to realize it??? If you race, I can guarantee you that you will be pulling that outboard off and tying her to the mast down below if you want to be really competitive. If it is just for your tender, you will hate lugging that 120 lb behmoth up and down the davits or mounting on the transom. The comments earlier about them being the preferred motor in the islands is what I have heard too and will tell you first hand soon.

My little Mercury 6hp has been an absolute PITA. It has been in the shop so much, I finally gave up on it. I cannot tell you how many time the carb has been rebuilt. It has reached the point of being completely unreliable. I have also had a Yamaha 8 4 stroke that was much more reliable, but still a bit harder to start than its 2 stroke cousin. Dad's 9.9 4 stroke is a good running engine, but getting that thing to lock up for shallow water is an act for Superman. You better check out how to and what acrobatic contortions are required to raise your 9.9 Mercury! I can tell you dad would not buy it again!

Oh, and my 2 stroke does not smoke any more than anyone's 4 stroke. SO put that debate to rest.

My very strong advice, contrary to what most have written here, is to get a 2 stroke if you can. The new ones are not like their old bretheren. I also believe that they have been driven out of the market not because they are not a superior product, but because of marketing and govermental influences.

But if you are gong to buy a 2 stroke, you better hurry.

Brian

PS The only clear advantage I have seen in the 4 stroke is for those that do a lot of low speed idling. It seems the 2's like to run versus the 4's which perform fine on all ranges of throttle.


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## LifeWorthLivin (Aug 30, 2006)

Cruisingdad said:


> Yamaha quit production on them this last summer in favor of the 4 stroke.


Cruisingdad,
Do you know if Yamaha just stopped selling them in the states, or actually stopped production? They are still listed on the Yamaha Mexico site, but it may just be out of date. I was planning on getting one in Mexico when I get down there next year, but if they have truly stopped production, it may be worth me getting one now.


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## eolon (Feb 5, 2008)

I have two one-strokes that came with my dinghy. They are the long, flat wooden ones that hook onto the gunwales. Evidently you have to pull on them at the same time to get them to start, although it's hard work and nearly impossible to get into reverse, so I don't recommend them.

Best Regards,

e

.::.


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## sailjunkie (Nov 4, 2009)

I was going to start a separate thread, to ask how reliable folks find the small HP 4 strokes, because I had heard that quite a few small HP 4 strokes are not as mechanically sound as small HP 2 strokes. However, the above replies at least partly answer that question. 

Has anyone had ANY bad experiences with small HP 4 strokes?


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## sailjunkie (Nov 4, 2009)

Whoops! Just saw CD's note. My sources match his experience.

That said, is his experience a comment on small HP 4 strokes; or Mercs? Our sailing co-op used to power the Catalina 27's with Merc 4 stroke 9.9's. Unfortunately, the motors could never take the pounding that some of our rookie members unintentionally deliver. After switching to 9.9 Yamahas, we found that while the pounding continued, durability increased substantially.

I originally asked about this because we currently own an "ancient" Nissan 2.5 HP 2 stroke. Now that we own our own boat and dinghy, I would like to get something that has a transmission. With that in mind, I'll be interested in where this thread goes.


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## 2Gringos (Jan 4, 2008)

People in the US seem to think that if they can't get two strokes, NOBODY can get two strokes. That is totally wrong. The EPA and the US government are the reason you can't buy two strokes in the US. For the rest of the world, they are preferred in many places. Its simplicity and power to weight ratio vs a four stroke's less noise and slightly better fuel economy under some conditions. Four strokes are more expensive to purchase, more expensive to maintain, and heavier for the same horsepower.

Wonder how much more energy and chemicals it takes to manufacture all the additional parts in a four stroke, and the spares for them.

As for the fuel and oil questions, both two and four strokes use fuel and oil. The two stroke gets some power from the oil. The four stroke oil gets discarded, somewhere.


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## jrd22 (Nov 14, 2000)

I just bought the neighbors old Yamaha 8 hp two stroke to replace the brand new Yamaha 4hp four stroke I bought last year. I was really disappointed in the noise and vibration of the 4, and when warm it routinely yanks the pull cord out of my hand (even though I'm ready for it) when trying to start it. The noise is what really got me, much louder than the Nissan/Tohatsu 9.8 hp two strokes that I have had for years (single cyl. vs twin?). The weight and complexity of the four strokes really doesn't make much sense to me, but they do burn nice and clean. Wish I could still buy a new two stroke.


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## T37Chef (Oct 9, 2006)

I really hate my Honda 2hp 4 Stroke! It sucks, really really sucks!!! And IMO its NOT quiet at all. I also had a Suzuki 6hp 4 Stroke a few years ago, hated that one too. 

Gas these days isn't helping these little engines at all, fuel stabilizers (some even say a little 2 stroke oil) seems to help. 

If I could find a 2 Stoke 6-8hp I would buy it in a second.


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## 2Gringos (Jan 4, 2008)

I feel for you guys. We can get whichever outboard we want here, two or four stroke, not just what Uncle Sam allows to be marketed. Keep in mind, while you can't find two strokes in stock up there, it's certainly not illegal (yet) to own them.

Hey, the closest place for a lot of you guys would be Mexico. And for those who keep saying this rubbish like "Yamaha doesn't make two strokes any more" blah blah...well. Bullpucky. They don't know what they are talking about. Common problem these days. check out the Yamahas, your choice, 2 hp up through 250 hp 2-strokes:

IMEMSA-YAMAHA, La mejor experiencia de navegar la Aventura


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## Cruisingdad (Jul 21, 2006)

2Gringos said:


> I feel for you guys. We can get whichever outboard we want here, two or four stroke, not just what Uncle Sam allows to be marketed. Keep in mind, while you can't find two strokes in stock up there, it's certainly not illegal (yet) to own them.
> 
> Hey, the closest place for a lot of you guys would be Mexico. And for those who keep saying this rubbish like "Yamaha doesn't make two strokes any more" blah blah...well. Bullpucky. They don't know what they are talking about. Common problem these days. check out the Yamahas, your choice, 2 hp up through 250 hp 2-strokes:
> 
> IMEMSA-YAMAHA, La mejor experiencia de navegar la Aventura


I was told by the distributor that Yamaha ceased all 2stroke production as of this last summer. I do not know if that was worldwide. DId not matter to me as I got one of the last ones.

TO the other responders that want a 2stroke, I would be shocked if you could not still find some. Just start calling Yamaha dealers. They would love to move them as most dealers keep the small engines only to satisfy Yamaha which requires they keep a wide variety in stock. There is no money in small engines so you will probably be able to pick it up for dealer cost (though I am sure there is a kick-back somewhere).

Hope that helps.

Brian


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## timebandit (Sep 18, 2002)

Yes, your bigger 2 strokes (2 cylinder) motor produces 4 times the power pulses per revolution as a 4 stroke (1 cylinder) does.

Most older small outboard engines use a mechanical advance system connected to the throttle so if you are starting your 4HP in gear and at cruising speed because the boat is heavy and the motor is small, you might want to try starting it at an idle to elimanate kick back.

If the above is not true then you might want to try a little choke or push in the primmer button once to see if that will help.



jrd22 said:


> I just bought the neighbors old Yamaha 8 hp two stroke to replace the brand new Yamaha 4hp four stroke I bought last year. I was really disappointed in the noise and vibration of the 4, and when warm it routinely yanks the pull cord out of my hand (even though I'm ready for it) when trying to start it. The noise is what really got me, much louder than the Nissan/Tohatsu 9.8 hp two strokes that I have had for years (single cyl. vs twin?). The weight and complexity of the four strokes really doesn't make much sense to me, but they do burn nice and clean. Wish I could still buy a new two stroke.


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