Used outboard: 2 vs 4 stroke

[guy48065]

You're looking at equivalent 20 year-old boats...2C vs 4C, and why?

[rancherlee]

Direct injection 2 stroke/EFI 4 stroke > carb 4 stroke > efi 2 stroke > carb 2 stroke as far as fuel usage goes, at ~20 years old your probably looking at Carb 4 stroke VS carb 2 stroke. It's not even close in fuel efficiency, 4 stroke wins in that case, especially if the price is the same/similar. A few late 90s 4 strokes were EFI like the Suzuki 40-70, and bigger Yamaha power head merc 4 strokes.

[guy48065]

Fuel efficiency is probably my least concern. I'm on a small inland lake, no marina, just occasional lap or 2 around.
I'm looking more at reliability, maintenance cost , weight, etc.
About all I know is 4C smokes less
I always believed for a given HP that 2C were much smaller and lighter...but...I've noticed around my lake plenty of newer 4C motors smaller than my 1980 Mariner (Yamaha) with equal or even greater HP. But that's not fair comparing motors 30 years apart. In thinking how much HP small car & truck engines make today.

[rancherlee]

If you can handle oil changes, the quietness of a 4 stroke alone is worth the extra cash $$$ over an old 2 stroke. I know you said economy is your least concern but your talking 2-3x better at trolling speed and 1.5-2x at mid range cruise over a carb 2 stroke, WOT is actually fairly close and maybe 20% better. That's the difference in fuel I seen going from a 70hp Johnson 2 stroke to a 70hp Johnson/Suzuki 4 stroke. 2 stroke, yelling to talk with other passengers at cruise, 4 stroke normal speaking voice at cruise. 2 stroke, quite a bit of "manly oil smoke smell" if your down wind, 4 stroke nada. 2 stroke, light wieght, 4 stroke 50-100# heaver in that era is about your only downfall, and paying for oil changes/500hr timing belt changes if you can't do basic service.

[guy48065]

In hindsight this was a stupid question. I'm not likely in my boat hunt to have 2 pontoons equal in so many ways that the decision might hinge on 2- vs 4-stroke. I'll buy based on price & condition of the boat and accept any type OB that it comes with (as long as HP and condition needs are met...).

Going after work to look at a Sweetwater with a 2C 50HP Yamaha. Yammie wouldn't be my first choice but a re-power adds too much to the overall cost. If reality = the pictures, description and conversation I'm coming home with it.

[guy48065]

The Search continues. ..

[JerEazy]

I've always been a 2-stroke guy. More torque, better hole-shot, easier to maintain. Smoke just means it's working. And a good working 2-stroke should only smoke a lot when first started.

Especially when you're talking older engines - the 2-strokes just seem to have a longer life

[justfishing]

At that age it would come down to condition and do you have mechanics that can fix them. Also availability of parts.

You might find it difficult to get parts for older suziki aND hondas.

There was a lot of transition in 2 strokes. Going from straight mixing oil and gas, vro oiling, efi and direct injection. Vro oiling systems can be good but when they fail it can take out the engine. Many people chose to remove them and mix the oil. Early direct injection motors had some serious problems.

20 years ago 4 strokes were not the common. Engines were heavy and like any carb engine not very fuel efficient compared to today's engines. 4 strokes have more moving parts and need valve adjustments.


Fuel quality and fuel age are very important and go a long way in how the motor runs and if you have major breakdowns. Ethanol in the gas is very hard on old fuel lines and need to be replaced.

A good place to ask motor questions is at bass boat central. Go to the motors section...boards for each brand. There are techs and highly skilled dyi that can tell you a lot about any motor. Fyi if you asK a question try to have model and serial number. They have good information on fuel lines. If a 2 stroke learn about the need to decarb the motor and how to prevent carbon build up.