2 stroke vs 4 stroke(2 motor scenarios)

[rsw21282]

I know 4 strokes have a better reputation for longevity and reliability but how big of a difference does it make? for instance i am looking at two boats one with yamaha 115 4 stroke 2003 or a merc. 90 2 stroke 2005. how big is the life of the motor difference(keeping in mind i would do all the appropriate maint. and flushes)? the merc. is also the salt water series, how big of a difference does that make? These are on 19' center console boats that i would take maybe 4-5 mi off shore weather permitting so reliability is pretty important.

 

[steelespike]

Re: 2 stroke vs 4 stroke(2 motor scenarios)

In my opinion 4 strokes are not necessarily known for longevity.
or reliability any more than a modern 2 stroke.There is a reason the 4 stroke has more frequent,more involved service intervals.
A 2 cylinder 2 stroke has 5 basic moving parts,a 2 cylinder 4 stroke has at least 28 basic moving parts.The 4 stroke will generally be turning more rpms per mile.Kind of like a car with a numerically high axle ratio.From a maintenance and longevity point of view I would be getting a 2 stroke.

 

[robert graham]

Re: 2 stroke vs 4 stroke(2 motor scenarios)

A well maintained 2 stroke with carbs is as bullet-proof as you can get. Clean, fresh, stabilized gas, a fuel/water seperator, drain carbs a couple of times a year, and you should be good to go. Whatever motor you buy, get a shop manual for it and study up all you can, check these forums for a wealth of knowledge and experience. My brother-in-law had the 115 Yamaha 4 stroke and it was a great motor until he got water in his gas tank, ruined injectors, lots of pain and expense, motor is still in pieces, really not good! I have a 1999 Yamaha 90HP 2 stroke premix, absolutely no problems for 10+years, runs like brand new! Good Luck!

 

[86 century]

Re: 2 stroke vs 4 stroke(2 motor scenarios)

+1 for 2 stroke if O/B are the same as dirt bikes you can rebuild the 2 stroke twice for what it takes to do the four stroke once. with that said I know nothing about four stroke O/B

 

[jevery]

Re: 2 stroke vs 4 stroke(2 motor scenarios)

2009 Marine Engine Competitive Information Study

"Among the four engine types included in the study, outboard EFI four-stroke engines have particularly high quality, with just 51 PP100." (DI engines average 73 PP100)

"In terms of satisfaction, it is a dead heat between two-stroke DI and four-stroke EFI outboard engines,? said Markusic. ?However, from a quality standpoint, EFIs clearly have fewer reported problems. In general, owners of EFI outboards tend to have fewer issues with the engine running rough or hesitating, unusual engine noises and fuel system leaks than do owners of DI engines.?

 

[Silvertip]

Re: 2 stroke vs 4 stroke(2 motor scenarios)

That has nothing to do with "longevity". It has only to do with current owner satisfaction and initial quality. Lots of things rated high in initial quality turn out to be junk down the road. As a comparison, there are tons of Johnson, Evinrude, Merc and other two strokes on the water in daily use that are 20, 30, 40, and 50 years old and never have been opened up for internal repairs. Now that's longevity. Only time will tell if 4-strokes will live that long. I predict not!!

 

[OldMercsRule]

Re: 2 stroke vs 4 stroke(2 motor scenarios)

That has nothing to do with "longevity". It has only to do with current owner satisfaction and initial quality. Lots of things rated high in initial quality turn out to be junk down the road. As a comparison, there are tons of Johnson, Evinrude, Merc and other two strokes on the water in daily use that are 20, 30, 40, and 50 years old and never have been opened up for internal repairs. Now that's longevity. Only time will tell if 4-strokes will live that long. I predict not!!

What he said^^^^^^^. Couldn't have said it better meself.

'Sides: 4 strokes are heavy, have lots of rotatin' iron ta make 'em run in the first place, and lack power, (as the 2 strokes are far more powerful over the entire power range, and it is doutful if the 4 strokes are even as powerful as a similar rated 2 stoke @ WOT [as rated] part of the Gubmint tolerated propaganda, wink..... wink....), could be all that heavy cornplicated iron n' all, eh?

It is all industry/Gubmint propaganda, (tastes like kool aid).

The PPM polution carp is just that: carp!

A far more powerful engine takes more fuel which makes more PPM carp to generate that much greater power; SHOCKIN' as it may seem.

Me overpiced $.02 JR

 

[moonfish]

Re: 2 stroke vs 4 stroke(2 motor scenarios)

I don't know if I understand this correctly but doesn't the only new two stroke available have it's oil controlled by some computer chip? Isn't that it's own liability? Am I completely wrong there?

 

[rsw21282]

Re: 2 stroke vs 4 stroke(2 motor scenarios)

Hey guys thanx for the posts it seems that four strokes arent all i had heard they are cracked up to be.

 

[jevery]

Re: 2 stroke vs 4 stroke(2 motor scenarios)

That has nothing to do with "longevity". It has only to do with current owner satisfaction and initial quality. Lots of things rated high in initial quality turn out to be junk down the road. As a comparison, there are tons of Johnson, Evinrude, Merc and other two strokes on the water in daily use that are 20, 30, 40, and 50 years old and never have been opened up for internal repairs. Now that's longevity. Only time will tell if 4-strokes will live that long. I predict not!!

The two-strokes that you speak of are far simpler machines than the two-strokes of today. As with the EFI, the DI systems are laden with sensors, silicone chips, and everything else needed to make these mechanisms work together correctly. As they age, it will not be the four stroke valvetrane that retires the engine. It will be the unavailability of parts for these subsystems.

I don't live near the coast, so I don't know which way the commercial fishermen lean, but I have heard they tend to favor the four strokes. This guy seems to have had good service from his.

OldMerc, I'd love to respond, but your ramblimgs leave me speechless.

 

[kenmyfam]

Re: 2 stroke vs 4 stroke(2 motor scenarios)

That has nothing to do with "longevity". It has only to do with current owner satisfaction and initial quality. Lots of things rated high in initial quality turn out to be junk down the road. As a comparison, there are tons of Johnson, Evinrude, Merc and other two strokes on the water in daily use that are 20, 30, 40, and 50 years old and never have been opened up for internal repairs. Now that's longevity. Only time will tell if 4-strokes will live that long. I predict not!!

Agree with this one 100%

 

[OldMercsRule]

Re: 2 stroke vs 4 stroke(2 motor scenarios)

The two-strokes that you speak of are far simpler machines than the two-strokes of today. As with the EFI, the DI systems are laden with sensors, silicone chips, and everything else needed to make these mechanisms work together correctly. As they age, it will not be the four stroke valvetrane that retires the engine. It will be the unavailability of parts for these subsystems.

I don't live near the coast, so I don't know which way the commercial fishermen lean, but I have heard they tend to favor the four strokes. This guy seems to have had good service from his.

OldMerc, I'd love to respond, but your ramblimgs leave me speechless.

"Speechless" eh? LOL

Let me clue ya in a weeeee bit about commercial fishermen, (I fished commercially this summer out of Cordova AK), and I have family that has fished fer over 40 years up there, (where the rubber meets the road).

Commercial fisherman in Prince William Sound or on the Copper River flats, (Bristol Bay, Cook inlet, n' SE tooo), do not use many outboards anymore AT ALL in their bidness endeavors. The Gubmint has forced all modern outboards to be very cornplicated to meet Nanny Gubmint imposed regulations n' they don't like to trust their lives to cornplicated hunks of junk. Can ya blame 'em?

If ya travel overseas ya get a much better idea of how much kool aid we have all been drinkin' here in the States. Fourstrokes are rare in fishing fleets outside the US, as are the DFI 2 stroke carp we see here where fools rule us and force low productivity; high maintenence n' and spew kool aid by the gallon that we all seeeeeem ta enjoy. Oh butt it tastes soooooooo good........... eh?

The simple old style carbed 2 stokes are referred to as "commercial" out in the real world and sell a lot of units outside the corntrol of central corntrol in Sacremento, (ya know the place that pays State beaurocrats with IOUs) n' WDC, the other place printin' lots n' lots of IOUs that you may have heard of.

Hope that helps ya understand what commercial fishermen do.

Respectfully, JR

 

[Silvertip]

Re: 2 stroke vs 4 stroke(2 motor scenarios)

A 1955 Chevy is currently 54 years old and you can still get parts for them. Down the road when the outboard engine manufacturers quit making parts for electronically controlled two/four stroke engines there will very likely be aftermarket suppliers that step up to the plate just like they have for the vintage Chevy, Ford, Dodge and a host of other autos. That market is already alive and well in the marine industry and has been for decades. Tune-ups used to be points plugs and condenser. There are other goodies on engines today that are replaced only if they fail so the "electronic controls" can be considered the modern day tune-up. Some engines will need new ones, some will never need them.