2-stroke vs 4-stroke

[Bwalker]

Re: 2-stroke vs 4-stroke

I have fixed Yamaha 6 and 8 hp motors miles back in the bush with only a Leatherman and a 10mm wrench.

 

[phatmanmike]

Re: 2-stroke vs 4-stroke

lol chief!!!!!

dock rates here are outrageous, so out to sea i go!

seriously. there are way more choices in outboard types now than ever. its completely up to you and what you feel comfortable with.

if you are gonna pay for ALL the maintenence and work, than by all means go for thee most advanced engine you like.

if you are a simpleton and doo the stuff yourself, than i would suggest a carbed 2 stroke. merc, yammy and johnny still make this in limited sizes .

myself, well, i wish they made turbo diesel or rotary outboards! yee haw

 

[jaymasta]

Re: 2-stroke vs 4-stroke

carbed 2 stroke

 

[cobra 3.0]

Re: 2-stroke vs 4-stroke

I don't mind carbed two stokes on smaller engines. Noise levels are bearable, smoke isn't too heavy, and gas consumption isn't really a concern. Portability is usually and issue so tewo strokes get my vote.

However, after having seen the newer four strokes run (including the Evinrude Etech), I really can't see the desire to hang on a larger two stroke carbed engine. I truly believe that this old technology is the most "bullet proof" and low maintenance, but to me the trade off in gas consumption, smoke, noise, shake, rattle and roll doesn't cut it.

 

[Silvertip]

Re: 2-stroke vs 4-stroke

The gas consumption difference between an EFI 2S and 4S is a non-issue as they are so close and in some cases the EFI 2S are better. Even comparing carbed 2S with 4S is difficult if compare wide open throttle consumption. Fact is it takes so much fuel to make so much horsepower. To get a ballpark estimate put a decimal point one position left in the horsepower rating. 100 HP = 10 gal/hr at wide open throttle. That number depends on the boat, load, wind, currents, etc but it is can be quite accurate. 2S and 4S will be quite close at WOT. The 4S will have an advantage at midrange throttle settings. 2S are simply better performers, less moving parts, and in my view, a better engine design for an outboard.

 

[cobra 3.0]

Re: 2-stroke vs 4-stroke

At WOT sure. At 2/3 throttle the difference is more than significant.

Here's an example. I have two older quads a 4 stroke 300cc Honda and a 350cc 2 stroke Polaris. The Polaris on a typical ride will consume 2 to 3 times more gas than the Honda! Granted we aren't blasting full out in trails. As we ride harder, the Polaris still consumes more but the difference is much less.

So, I suppose if you drive your boat at WOT everywhere there isn't much benefit of going 4 stroke...which might be the case because we aren't talking big horsepower here.

 

[rottenray6402]

Re: 2-stroke vs 4-stroke

One thing I would consider is what brands are most popular around your area. It is discouraging waiting several weeks for parts for one brand when the marina down the street stocks stuff for another brand. I have no idea how difficult it is to get parts in Norway but it was always a consideration when I lived in Alaska. As far as personal experience all I can afford are old carbed 2 cycles! :'(

 

[Silvertip]

Re: 2-stroke vs 4-stroke

Cobra -- the difference here is you don't deal with slippage with a land-based vehicle and rarely run wide open throttle nearly as far as one does with a boat. With a boat the engine is almost always full throttle getting out of the hole and generally 3/4 or more with a load. The Yamaha web site (Performance Tests) has very good test data on both two and four strokes on various types of boats. Check it out. 2S has no oil changes, no valve adjustment, no timing belts to break, and the modern two strokes as clean or cleaner than 4S. The next step in 4S evolution will be where to put the catalytic converter.

 

[Bwalker]

Re: 2-stroke vs 4-stroke

Who cruises around at 2/3 throttle?

 

[cobra 3.0]

Re: 2-stroke vs 4-stroke

Me with my 3.0 inboard and that still gives me about 22 mph cruising for water skiing, tubing, and knee boarding with the kids. However, as I mentionned above, this is probably not the case in this horsepower range, 40 -60hp.

(Granted in my 14 foot tinny, my 15hp 2 stroke Evinrude is WOT all the time except when trolling. Same thing on my 12 foot toon also with a 15 hp Evinrude.)

 

[steelespike]

Re: 2-stroke vs 4-stroke

I'm sold on the etecs I saw a 40 tiller the other day.And was amazed at the smooth quiet operation and there isn't a cleaner engine out there and we're talking it's a bunch cleaner.

 

[dingbat]

Re: 2-stroke vs 4-stroke

[quote ]Who cruises around at 2/3 throttle?[/quote]

Me with a 225 HP Rude bolted on the back. The speed difference in not significant but the fuel savings is substantial. To the tune of 1.6 mpg compared to 2.4 mpg.

I would consider a 2S in a small HP motor but no way in the larger HP. You can't hardly give away a large 2S anymore

 

[JasonJ]

Re: 2-stroke vs 4-stroke

Hey Seahunter, you can give me a large 2 stroke any day.

I love the new Etec and it is probably the only new motor I would want. I end up with old motors because that is all I can afford. I would never make up the difference in initial purchase of a new motor with saved fuel costs. The only reason I will ever buy a new motor is because I finally earned enough to afford a new boat.