2 stroke vs 4 stroke

[Tn Jim]

I am going to finally get my own boat in the spring. I am looking at a Tracker 170. It comes standard with a 50 hp 2 stroke engine. For a fee, I can get that changed to a 40 hp 4 stroke with EFI. What are the pros and cons of each? Is the 4 stroke with EFI worth five hundred  more and be 10 horses smaller? I need some info before I waste money or make a bad decision. Thanks guys.

[Empty Quiver]

My opinion and that is all it is. If you plan on using it a bunch a 4-stroke can save you money, fuel efficiency. If you plan on trolling a bunch a 4-stroke is better suited to idleing around. The 2-strokes are smaller and lighter especially when power output is equal. No oil changes on the 2-stroke.

I like just about everything about 4-stroke, but in a boat, the way I use one I would likely stick to a 2-stroke. It would take me forever to justify the added cost, and in a smaller boat the added weight would be unwelcome.

[Rex in OTZ]

2 storkes have less efficent fuel economy but the power to weight ratio is greater than the 4-stroke.
The 4-stroke weighs allot more and costs allot too as compared to a 2-cycle.
Anymore they will phase out 2-cycles they arnt as prevlant as they were 10 years ago in the outboard motor lineups of major mfg's.

If you were useing a Zodiak and pulling it over sand bars and weight was a issue the 2-stroke would be the better choice, also by adding a 4-stroke on the back adds extra weight so may have to consider balanceing your boat, may may have to move the fuel tanks and operator placement, especially on a work boat.

[hillbill]

ive not had a lot of experience with 4 stroke boat motors, i have had tons of experience with 2 stroke boat motors. the 2 strokes are fine but ive always had trouble with them after they get a few years old even when the gas is stabilized etc. now i have had a ton of experience with 2 and 4 stroke dirt bikes.2 strokes are always a pain, 4 strokes just keep on running fine.yu might have to clean the carbs every few years but not every year like on a 2 stroke.i bought a new merc 50 in 02 and really wanted the 4 stroke honda but it was 2k more.the merc is dooin fine but ive been into the carbs a couple times and now its stuttering again.if the diff was only 500 buks id go for the 4 stroke motor. they are the wave of the future and will have more resale.id think the fuel mileage alone would be worth it.in a bike a 4 stroke will get maybe 20-30% more mileage, now im not talkin mopeds im talkin bigger hp engines.yea they weigh a little more per hp but id go for it.

[Rex in OTZ]

The 2-cycle outboards I used were older Yamahas (90hp) that had a seperate oil injection, Not premixed.
I did work on some older pre-mix 15hp, 25hp, 35Hp Evinrude and Johnson outboards but traded that all off for new Yamaha F15 and 2 cycle 25Hp tillers for inflateable boats (25's were the last new 2-cycle yamaha's I could get)
 like anything fuel quality is paramount, in my particular area we had allot of Brakish water and fine silt that when dried & dusted up got on and in everything. fuel filteration cannot be stressed enough for mainly water be it inboards or outboards will ruin them in short order.
I drain the carbs regulary due to our problematic Alaska Bush fuel handling, leaving water in carbs causes aluminum corrosion problems blocking all your jets and restricting air & fuel passages.
I had a Merc inboard jet come through the shop with a power problem, the carbs all had enough water in them to fill a shotglass, when I dissembled the carbs they had lots of fuzzy white chalk like corrosion in every one them, I had to go through every carb jet by jet, the Merc 210 has 3 dual carbs each one is jetted differently so dont swap em round.
Gassing out at a Camp from a fuel drum, if the bung is tightened the drum wont vent properly and bulge like crazy and at night will turn into a 3 sided drum, during the day they heat & expand and off gas and when cool the draw in moisture laden air especially during cool days or if its rain water that collects in the bottom of the drum, gas cans, and hull mounted tanks, in every one them Ive found a bit of water, I now pump out the gas tanks and swab em dry with a rag on a wire, then treat the gas with Stabul and MrFunnel (water trap funnel)the gas back in the gastanks and run and Fog the motor for winter and wrap the motor with duct tape & tarp (out doors storage) for over winter storage.

[Tn Jim]

After doing a lot of research I have decided on the 4 stroke. Maybe a little heavier and not quite the UMPH of a 2 stroke, but the better mileage and easy going nature of the 4 make it more appealing to me. Either one would be winterized and maintenced correctly, but the introduction of ethonol into our fuel seems to wreak havoc on the carbs in boats. The EFI system looks better to me for that reason. I just hope the 4 stroke EFI engines prove to last as long as the 2 strokes have. Thanks for all your help guys.

[Rex in OTZ]

Caution running some EFI models dry (out of gas) like Yamaha F75, will tear off a small chunk of pump rubber seal and send it down the injector line and either restrict or clogg the injector you will encounter a reduction in power or you wont get full throttle and may burn up that cylinder/cylinders from the resulting lean condition.

[eye shot]

I run a 115hp. E-Tec on a 18 1/2' Starcraft Super Fisherman and it gets better fuel economy than any of the four strokers I run with.

[Rex in OTZ]

The guys in town that do own them like them, them they do complain about paying $115 a gallon for the special injection oil (our cost in the Alaskan Bush).

[PartsMan]

The valve train on a two stroke is the kind of simplicity I want in the water.

[MGMorden]

Good decision on the 4-stroke.  I recently was faced with the same decision.  Bought my boat (a Triton Storm 16) around July of last year, and I was debating between a 40hp 4-stroke or a 50hp 2-stroke.  I had intended to get a 50hp 4-stroke for the boat (figured while I was buying I might as well max out the hp), but the dealer didn't have any of those in stock and I wanted to take home the boat that day(it was a 2.5 hour drive to the dealership to get the exact boat I wanted, so I didn't want to come back if not needed).

In the end it simply came down to frustration levels.  My brother's boat (a 15' welded jon) had a 2-stroke (25 hp Johnson pre-mix)  that was full of gremlins.  Temperamental to start, burned fuel like crazy - overall just not a good experience.  Everywhere I read said that the 4-stroke needs a bit more preventative/standard maintenance like oil changes and the like, but that aside from that, they're less troublesome.

I ended up getting the 40hp 4-stroke Mercury.  Works great.  My dad has a boat similar to mine - an older Crestliner 16' and he has a 40hp 2-stroke Mercury (not pre-mix - uses an oil reserve).  I've driven that boat a lot, and though it may clock in just a LITTLE faster than mine, the difference is pretty much imperceptible.  What is different is the gas burn.  On his 12 gallon tank he gets 2 or 3 fishing trips.  On my 12 gallon tank I get 5 to 7 trips.  Also, I just took my boat out for the first time this season on Sunday.  Hadn't been ran all winter (I live in a relatively warm climate so I don't bother winterizing).  Engine cranked up and ran flawlessly at the first turn of the key. 

BTW, after riding in my boat a few times with my 4-stroke, my brother has since ripped that old troublesome 2-stroke off his boat and went and bought a 4-stroke Merc as well.  He actually not only went 2 to 4 stroke, he also downsized from 25hp to 15hp, and he still likes the new engine more simply due to the ease of starting and lower gas bills.

Also, though this wasn't nearly as big a factor in my decision, the 4-strokes when running right don't tend to smoke at all.  2-strokes almost always seem to smoke some.  Age and/or condition will determine whether it's a little or a lot of smoke, but they all seem to do it.  Also, the 4-stroke is much, MUCH quieter while running. 

While the 2-stroke does have a few advantages (as stated - lower weight and a bit more punch when getting up on plane), overall the disadvantages seem to outweigh those.  There's a reason why the entire industry has pretty much moved away from them.

[alan in ga]

I've now owned a 40 Mercury 4 stroke on a Triton 1653SS [stick steer] for about 5 months. I LOVE it. I've owned 8 boats, all 2 stroke until this last one. When I first heard it crank, it ran a fairly fast idle, then started to wind down to sounding like it would surely stop. Nope, idled down from a fast idle to a very slow idle purrrrrrr. EFI at work! This motor, in about 10 outings, has NEVER stopped or stalled. It uses very LITTLE FUEL!
It does not have the strong midrange torque of the 2 strokes, but all the other benefits have me not missing that. When you throttle it up, it just smoothly winds up thru the rpm and gets you where you're going quietly!
Yep, I'm a convert. LOVE the 4 stroke.

[eye shot]

MGM
To bad you didn't look at the 2 stroke E-Tec it's lighter, just as quiet, don't smoke at all even on idle, and gets better fuel economy or at least as good. It also winterizes itself. I did alot of research befor I bought mine and every thing they claim I've found to be true.

[SHOOTALL]

I have a 2 stroke 30 my son a 4 stroke 30 . we can talk in his boat while under way. He uses less gas . They run about the same speed . I buy oil and add it to fuel every time , his filter and oil are expensive so its a wash out. Some lakes around here are talking of limiting 2 stroke engine use or out right banning it.