Can someone clear a few points on 2 and 4 strokes for me please

[khc1970]

not trying to re-ignite another debate on 2 stroke vs 4 Strokes, but can someone answere the following questions for me please.<br /><br />1) 4 strokes better fuel economy (in general, not going to argue on new Di claims' better economy than some 4's), overall, cruising or max?<br />2) Does a 2 stroke 70hp (example) has the same power and pushes a boat to the same speed as a 4 stroke 70hp presuming the set up is the same?<br />3) Any different at cold start or idle?<br /><br />I'm more interested in the running/practical characteristics/differences of an outboard rather than the underlying mechanical differences.<br /><br />Thanks in advance.

 

[Guest]

Re: Can someone clear a few points on 2 and 4 strokes for me please

Not quite sure waht you're looking for but here's my 2 cents:<br /><br />Last year I traded a conventional carbed 2 stroke (2003 merc 2 stroke 50hp) for a new e-tec. I also fish with my brother a lot who has a four stroke. <br /><br />The real difference is between the old 2 strokes and the new motors. Both the four strokes and DI 2 strokes are far superior. My new motor does much better on gas and and is really better in almost every other way, too (smoothness, starting, smoke, slow trolling speed, etc.). I will say the old one was faster, though.<br /><br />Even though i have an e-tec, I'd say most of the new style motors are excellent.<br /><br />Hope this helps, Bill

 

[Silvertip]

Re: Can someone clear a few points on 2 and 4 strokes for me please

I'm not sure what you after with question 1 but here goes":<br />1) Evinrude E-tecs (two-stroke DI) are every bit as economical and pollute less than four-strokes. Other two-stroke DI are similarly as economical as four-strokes. There is no debate on this.<br />2) 70 HP is 70 HP. Two strokes generally have better hole shot than four strokes and in my view, are much better suited for sustained high-speed operation than four-strokes. Same prop, same boat, same gear ratio at same rpm should produce the same speed (theoretically). Due to engine weight differences that may not always be true. Some four-strokes are about the same weight as two strokes. As you get into larger sizes weight generally favors two-strokes.<br />3) Fuel injected and DI both provide turn-key starting. Two-strokes are ready to go almost immediately, some four-strokes tend to be more cold blooded and need a little more warm up time.<br />Four strokes have a very slight edge on quietness. I think four-strokes are going to see higher long term repair bills than two-strokes and probably somewhat lower life expectancy. You will very likely get differing opinions on my comments but that's what makes life interesting. There simply is no utopia.

 

[JRJ]

Re: Can someone clear a few points on 2 and 4 strokes for me please

1) An EFI 4-stroke will give significantly better economy than the same HP carberated 2-stroke.<br /><br />2)70HP is 70HP. The motors weight will affect performance some.<br /><br />3)EFI motors start and idle better, (2 or 4-stroke).

 

[khc1970]

Re: Can someone clear a few points on 2 and 4 strokes for me please

Sorry, should have made my questions clearer, I was refering to moden Di 2 stroke to EFi 4 strokes.

 

[beniam]

Re: Can someone clear a few points on 2 and 4 strokes for me please

Hi khc1970 Here is my tuppence worth.<br />Here are some comparisons I have gleaned from the Nissan outboard motor people.Using their engineers data:<br />For a 70 hp comparison; wot,3 cylinder vs 3 cylinder, same displacement: 2 cycle vs TLDI 7.4 gph vs 6.4 gph. Savings 14% more efficient favoring TLDI.<br />Comparing 25 hp 2 stroke with 25 hp 4 stroke;wot at3.3 gph, vs 2.2 gph, a 27% savings for the four stroke. For medium to small motors, a two stroke is lighter, you can check your own weight from any manufacturers pamphlet. Personally, 4 strokes are quiet and so sweeeet. Batavier.

 

[steelespike]

Re: Can someone clear a few points on 2 and 4 strokes for me please

It appears the Etec has better hole shot and higher speed than the Merc. Verado.Also is smooth quiet and clean.In my opinion any 4 stroke has just to many moving parts to be pratical in the long run.(something like 200 parts in the heads alone).2 stroke has fewer parts easier maintenance less down time.And the Etec has an unheard of 7 year warantee.I am not that impressed with my 88 Evinrude 50 from new but if the Etec is half what they claim Im sold.

 

[rodbolt]

Re: Can someone clear a few points on 2 and 4 strokes for me please

well check all the sales literature. ask any salesman.<br /> DFI never breaks and with a 4 stroke not only will it never break but will serve breakfast on saturdays,.<br /> good thing Maytag aint on my shirt.

 

[ED21]

Re: Can someone clear a few points on 2 and 4 strokes for me please

Now if they could only launch & retrieve my boat. That would be sweet.

 

[JRJ]

Re: Can someone clear a few points on 2 and 4 strokes for me please

Now, do you want to know which oil to use?

 

[khc1970]

Re: Can someone clear a few points on 2 and 4 strokes for me please

Should I use synthe....... only joking

 

[jtexas]

Re: Can someone clear a few points on 2 and 4 strokes for me please

but can you live without that sweet smell of 2-stroke engine oil burning at sunrise?