What if any advantage do 2 cycle outboards have over 4 cycles

[Doug_FL]

Is there any reason to get a 2 cycle outboard these days. My understanding is that high internal pressure (from compression) is what is necessary to get performance out of an internal combustion engine. In the past anyway, 4 stokes had an advantage in compression. I also notice law enforcement using 4 cycle engines on their craft, as opposed to 2 cycle. I think 4 stoke is also more fuel efficient. 2 cycle used to give more horsepower, in a small package. But, I'm not sure that is true any more.

 

[mjf55]

Where is the popcorn icon when you need it.

I think there are many discussions here on this topic.
Here is 2 that come to mind
Weight
Simplicity of the power head

Edit: try this google search
2 vs 4 stroke site:forums.iboats.com

 

[gm280]

:welcome: board Doug_FL. Nice to have you as a new iboat member...

Well one things 2 cycle engines have over 4 cycle engines is there are a lot less internal parts. And the translates in to less part failures and weight in the scheme of things. True 4 cycles engines are suppose to get better fuel economy, but I have never actually compared two identical HP model to see. The fact that 2 cycles engines don't have any engine oil to worry about makes them easier to care for. Just mix the fuel and go. On the flip side, 4 cycle engines are quiet and there is no burnt 2 cycle oil smell out of them. And it seems the EPA will one day outlaw 2 cycle engines, or not allow any more to be built. Remember there are tons of 2 cycle yard equipment engine out there as well. JMHO

 

[GA_Boater]

opcorn: Found some, mjf. LOL

Both have advantages and both disadvantages. Older two strokes are not allowed on some lakes if they aren't EPA/CARB emission compliant. and the 2 strokes that are compliant are complicated beasts - Merc Optimaxs and Evinrude E-TECs.

 

[jimmbo]

Better power to weight ratio, no messy engine oil changes, no valvetrain to fail, exhaust pulses can be utilized for tuning purposes, much better holeshot, useful in water sports and can get you to your destination and back in the time it takes the 4 stroke to get on plane

 

[Scott Danforth]

Welcome aboard.

Better power to weight ratio
Wider power band
Simple maintenance
About 20% lighter

 

[roscoe]

a 2 stroke outboard is the easiest way I know to get my s cycle oil fix.

I'd have to find a different way to get my tcw3 fix if I ever got a 4 cycle.


Do they make tcw3 incense ?

I could use a little table top boat model as an incense burner.

 

[Snoopy11]

In addition to previously posted comments, the upfront cost for a 2 stroke is less. At the end of the day it depends on what factor(s) do you value the most?

Interesting comment by GA_Boater:

2 strokes that are "EPA" compliant are complicated beasts.

Did not know this part.... Hummm

 

[82rude]

Snoopy11 remember 4 strokes are very complicated also.Most are computer controlled ,fuel injected ,with many moving parts.Due to govt emission reg the day of the simple uncomplicated outboard is over and done with.

 

[Snoopy11]

Snoopy11 remember 4 strokes are very complicated also.Most are computer controlled ,fuel injected ,with many moving parts.Due to govt emission reg the day of the simple uncomplicated outboard is over and done with.

Thanks 82rude! good point...

 

[Sea Rider]

Dough FL,

Which brand HP model are you interested in ? now a days there's a mixture of carbed, injected models throughout the portable and larger HP range. Will depend entirely on fabricator brand. Choose whichever model HP fills your boating requirements.

Happy Boating

 

[82rude]

I can see a future where other than portable, carbed outboards will be nonexistent.Loook at the auto industry,is there even a carbed motor sold today other than hot rods?And even there fuel injection in one form or another is taking over.

 

[Sea Rider]

It's a pitty that US, Canadian, European markets have banned or restricted 2 strokes outboards use/imports.The rest of the world are still using/buying them along manufacturers still manufacturing large HP models now a days for other worldwide markets.

Happy Boating

 

[Guest]

I think 2 strokes are near and dear to us old timers, 4 strokes are slower and heavier, but to a new boater, whose never owned a traditional 2 stroke, he will never miss the lightweight and (almost) carefree performance.

Me? and many others on this thread, grew up with them, love them , and yes, the exhaust smell does bring back fond memories, but I never thought it to be foul. Most of these 2 stroke engines are smoke free anyway once they're warmed up.

I have a clean 98 200 Ocean pro that I can bring back to hour 1 for $3600, a new 200 hp OB is around 15K+, I can buy a lot of gas and oil for that kind of money, and if i had to amke a new motor payment each month, how much money would I really be saving?

 

[dingbat]

I don't know a single commercial guy that still runs 2 stroke. "Oil" / fuel economy and longevity are the two biggest factors.

4stroke provides a 30% increase in fuel economy over carbed 2stroke. Don't burn thru $15 - 20 a day in 2 stroke oil.

3-5 k hours are common place. Pretty much Immune to the oil, fuel delivery and water ingestion issues associated with premature death in 2stroke

Oh, did I mention quiet? As in you can actually have a conversation with your crew why running 4500 rpm down the Bay. Can't tell that they are running @ the dock

 

[bruceb58]

When I was looking at used pontoon boats, it it had a 2 stroke, it was off the list. My Mercury 90(Yamaha head) is a very quiet motor. You can barely hear it idling.

 

[82rude]

Not all 2 strokes are noisy.My 60 etec is as quite as any 4 stroke at idle or full throttle and just as fuel miserly also.This summer for the first time ever I got somebody else to drive the boat on the trailer as I was waiting by the truck and I'm yelling at my brother to start the damn motor!Needless to say he told me I'm nuts its already running.Granted older s strokes are much more noisier.

 

[jimmbo]

It is sad that boat launches are no longer Mosquito free zones. All that smoke was good

 

[MH Hawker]

a 2 stroke outboard is the easiest way I know to get my s cycle oil fix.

I'd have to find a different way to get my tcw3 fix if I ever got a 4 cycle.


Do they make tcw3 incense ?

I could use a little table top boat model as an incense burner.

nothing like the smell on a early fishing morning

 

[Chris1956]

OK, I guess I can add one more thought. New Outboard motors whether they are 4 or 2 cycle are quite complex. A lot of the technology in new cars has been ported to outboards. They are direct fuel injected, and have a multitude of sensors and other electronics. For example, my 2014 Mazda injects gasoline into the combustion chamber after the valves are closed, just like e-Tec and Optimax inject gasoline into the combustion chamber after the ports are closed. They also have the required electronic sensors to support that technology. The real difference is that outboard motors need to function in a salt water environment. Salt and electronics do not play well together.

​I am not sure either type of new motor has simplicity, light weight or a power advantage anymore. If I was planning to buy a new motor now, I would be looking at power-to-weight ratios to see if the 2 cycle DFI motors have any advantage there. If not, I would go 4 cycle, since economy is about the same, and 4 cycle motor technology is more shared with the automotive world.