Two Stroke vs Four Stroke?

[oceansbreeze]

Howdy again!<br /><br />I have a question regarding 2 strokes vs 4 strokes. While I know the 2 strokes require oil injection, or oil mixed, and 4 strokes run on straight gas, how does this translate to making a new engine purchase decision?<br /><br />Looking at several boats, (still haven't been satisfied with whats on the market) stumbled across a dealer 30 mins away who sold Tahoe Boats. It comes with Merc 90 ELPTO but for $3,500 more, can have the foud stroke ELPT.<br /><br />There's also a Merc Optimax 90 for $2,900 more...<br /><br />I also looked at a Nordic 17'er that the dealer had a 4 stroke Merc 75 which was maximum rated, but would accept a 90hp 2 stroke as maximum. Obviously, I could probably get the 90hp 2 stroke for several thousand dollars less... such a dilemma!<br /><br />I have read the FAQ page at mercruiser.com about 2 stroke vs. 4, but looking for comments from experience. Hopefully, somebopdy can shed some real light on the 2 stroke vs 4 stroke so I can make a bit of an informed decision. Thanks!

 

[Silvertip]

Re: Two Stroke vs Four Stroke?

To confuse the issue even more, there currently are two generations of two strokes to choose from. Conventional carbureted and direct injected. Don't confuse direct injection with oil injection. Oil injection is used with both. Direct injection refers to how fuel gets to the cylinders. Compare direct injection to fuel injection on the four stroke. DFI two strokes are now nearly as quiet and are as fuel efficient or even moreso than some four strokes. So, think of carbed two strokes as "old" technology, DFI as "current" technology, and four strokes as -- well -- "new/old" technology for outboards. Mercury's Optimax and Evinrude E-Tech designs represent the latest in quiet, efficient, two-stroke power. Two strokes still enjoy a favorable weight advantage over most four-strokes and because of that, some performance advantage. No oil changes on the two strokes, nor are there any timing belts to wear or break, or valves to adjust so maintenance is considerably less on a two stroke. As for preference -- you pays your money and takes your choice!!!! E-tec gets my vote! I'm sure the Mercury folks will suggest Optimax. If money is a serious issue, you might want to consider a carbureted engine but it will be to your disadvantage down the road at trade/sale time.

 

[steelespike]

Re: Two Stroke vs Four Stroke?

Heres my 2 cents worth.Ive been running outboards and working on motors for 55 years.<br /> While 4 strokes are fine motors generally quiet,smooth and clean.They are more expensive to maintain than a 2 stroke. There are just too many moving parts.Just a rough estimate 3 parts per cylinder on a 2 stroke,and about 20 per cylinder on a 4 stroke.When you run a 4 stroke at wot on a regular basis it is like running your car at 110 mph everytime you use it.Even if the motor holds together it is going to need more<br />service than a 2 stroke.And with the apparent excellent success of the Evinrude etec the 2 strokes have it. Easier maintenance and apparent excellent reliability.With the etec success you are going to see more 2 strokes with clean quiet<br />powerful reliable operation.Even if the 4 stroke<br /> is the exact equal on all points it still will have too many moving parts.You have to wonder<br />if the perfectly fine 4 stroke outboard could become a white elephant to the modern 2 stroke.<br /> I'm not likely to buy a new outboard at this point in life but if I was I would be giving all the 2 strokes a very close look.

 

[BillP]

Re: Two Stroke vs Four Stroke?

Here's my 02. I've been running a 4 stroke about 9 yrs and carbed 2 strokes since the late 50s. I run both now. Let me preface with the fact that I originally bought the 4 stroke only to eliminate smoke in the cockpit and that problem is minor to non-existant with modern DFI 2 strokes.<br /><br />Carbed 2 strokes will eat the lower purchase cost difference up quickly by using more gas & oil. My preference is carbs so I can work on them but in this case I would elimate the carbed 2 stroke because they are major gas hogs by 40% more. Check your cruise range and fuel capacity if deciding the fuel burn of a carbed 2 stroke is ok. It may make a difference to you.<br /><br />The DFI 2 stroke and 4 stroke (carbed or EFI) share approx the same fuel burn. My 4 stroke is carbed and I would buy carbed again if going 4 stroke. Fuel burn is still unbelievable with the carbs and I can work on them. You have to do DFI on 2 strokes to match fuel burn of 4 strokes. <br /><br />"My bad" on 4 strokes...They need valve adjusting, crankcase oil/filter changing and attention to timing belt maintenance. I don't care how great they are supposed to be...these items are more hassle than pouring oil into a 2 stroke. <br /><br />The 2 strokes require dealing with oil and an occasional decarb. Decarbing is less an issue these days with clean burns and better oil. Plug fouling is history compared to the "old" days. I see no difference in plug changes between my 4 stroke and mid 80s/early 90s carbed 2 strokes. Both troll for hours without a miss but the 4 stroke is smoother, quieter and has no smoke. <br /><br />Considering which lasts longer...2000-3000 hrs is no problem for 2 strokes and is plenty for me. IF a 4 stroke does better I really don't care. I won't buy based on supposed "longer" engine life because I won't see it. <br /><br />At this point my choice would be a 2 stroke...etec first and other brand DFI second. In my opinion, less parts, less general maintenance and less hassle. Merc products wouldn't be on the list.

 

[Dhadley]

Re: Two Stroke vs Four Stroke?

Plus Bombardier just announced they are dropping a bunch of the 4 strokes from the line and repalcing them with 2 strokes. Hummmm....

 

[TOHATSU GURU]

Re: Two Stroke vs Four Stroke?

Two-stroke good....Four-stroke bad.

 

[khc1970]

Re: Two Stroke vs Four Stroke?

I recently bought a TLDi 90 for my 6m pilot house. Yesterday was my first day out on it. it was a pain breaking it in (pain being sitting around at low speed for ages), first 10mins 2000 rev, 1hr 3000 rev, 2 hr 4000, wot after 10 hrs. <br /><br />Before the Tohatsu I had a 1989 Mercury 100 2+2. The new outboard isn't as quiet as I was lead to believe, BUT I can talk without having to shoot at 4000 rev. Since I never been on a boat with an E-tec, I have no idea how quiet they are. However, it is a quieter than my friend's Optimax 150. <br /><br />Fuel economy is better, a lot better. I once did a similar run to the one yesterday on my Mercury, it drank over 10g of lead free. Yesterday the TLDI 'sipped' about 6 gallon. I reckon it would have been a lot less had I not been sitting on 3000 rev for an hour and at the rev, the boat never planed. Fuel savinf alone is close to £20.<br /><br />Yes they cost around the same as 4 strokes but without the expensive service charges. A friend has a Honda 30 and it cost him £200+ a year. My dealer says it will cost me around £100-£150 per year. <br /><br />There is no smoke even I'm only using the Tohatsu semi syn. <br /><br />If I was to get another outboard, the only thing I will change is that I will try to get a ride on each of the outboard considered, to make my judgement from it.

 

[TheChad]

Re: Two Stroke vs Four Stroke?

Originally posted by BillP:<br />At this point my choice would be a 2 stroke...etec first and other brand DFI second. In my opinion, less parts, less general maintenance and less hassle. Merc products wouldn't be on the list.

What is wrong with Merc products?<br /><br />-TheChad

 

[oceansbreeze]

Re: Two Stroke vs Four Stroke?

IT doesn't seem like they are knocking the Merc's - I love Merc myself - but I am goign to go visit my Evinrude dealer tomorrow and compare.....definitely decided to stick with 2 stroke - and the quieter E-Tec seems to have some advantages.<br /><br />It's hard to consider somethign other than the brand we have always considered the "best" ... I always said no to Johnson, and Yamaha, and honda..... and even Evinrude - but they at least warrant having a look see for me...<br /><br />All of you guys, your responses really helped me understand clearly. Makes me more set on NOT buying a stern drive, too many costly potential problems to worry about. Now I remember why I loved my Glastron so much (never ever had to have anythign repaired, just changed the plugs for over 4 years) and my OMC Ford engine spent as much time in the shop as it did on the lake.<br /><br />Anyone know where I can find a comparison of the Etec vs the Mercs?

 

[TheChad]

Re: Two Stroke vs Four Stroke?

I have been looking at boats for about the last year. No matter what dealer i go to, weather it was for Lowe, Tracker, Crestliner, Lund, etc.<br /><br />All the boats were priced with Merc's... Most of the dealers sold Evinrude's, yamaha, honda, Johnson, or any combination of those engines, but every new boat they sold was priced with a Merc, every dealer when i asked about that, said they have not had any problems with Merc's.<br /><br />So that makes me wonder... Are they pricing them with merc's because they are good engines and don't have many problems? Are they pricing them with merc's because they are the cheapest? Are they pricing them with merc's because of a contract? or what?<br /><br />-TheChad

 

[TOHATSU GURU]

Re: Two Stroke vs Four Stroke?

All of the engine brands( except one) that offer a DFI engine had problems at some time in the past with design. Mercury's Optibomb was number two in the list of dismal failures. But they fixed them and now they work fairly well.<br /><br />Since Mercury owns a great many boat lines and has sweetheart deals with many independent boat builders, it's not unusual to find a lot of boats coming pre-packaged with Mercurys. The next most common packager is Yamaha. Price is always the reason on the independent manufacturers and job security is the reason for the boat lines that Mercury owns.

 

[dajohnson53]

Re: Two Stroke vs Four Stroke?

Originally posted by Upinsmoke:<br /> To confuse the issue even more, there currently are two generations of two strokes to choose from. Conventional carbureted and direct injected. Don't confuse direct injection with oil injection. Oil injection is used with both. Direct injection refers to how fuel gets to the cylinders. Compare direct injection to fuel injection on the four stroke. DFI two strokes are now nearly as quiet and are as fuel efficient or even moreso than some four strokes. So, think of carbed two strokes as "old" technology, DFI as "current" technology, and four strokes as -- well -- "new/old" technology for outboards. ...

Aren't there actually three types of two strokes - carbureted, electronic fuel injection, and direct fuel injection?

 

[Dhadley]

Re: Two Stroke vs Four Stroke?

And several versions of the DFI's.

 

[walleyehed]

Re: Two Stroke vs Four Stroke?

Anyone know where I can find a comparison of the Etec vs the Mercs?

There is no comparison....Merc has nothing to compare to the E-Tec....

 

[Silvertip]

Re: Two Stroke vs Four Stroke?

If we are going to further refine the discussion, lets not overlook supercharged, fuel injected, four-strokes.

 

[TOHATSU GURU]

Re: Two Stroke vs Four Stroke?

Some people like E-tec,<br /><br />Some people like Optimax,<br /><br />Some people like HPDI,<br /><br />Of course the really bright ones like TLDI.

 

[walleyehed]

Re: Two Stroke vs Four Stroke?

If we are going to further refine the discussion, lets not overlook supercharged, fuel injected, four-strokes.

As I said, for comparison sake, apples to apples, there IS no comparison to the E-Tec....

 

[TheChad]

Re: Two Stroke vs Four Stroke?

If you are going to specify one speciffic type of engine and say that there is nothing that compairs to it, then you need show proof and tell why that one type is soo great.<br /><br />Saying E-tec is better then everything else, and not giving any proof or valid reasons, means you are giving a Bias Opinion.<br /><br />-TheChad

 

[Dhadley]

Re: Two Stroke vs Four Stroke?

I dont think he's necessairly saying its better (although they should be), there just isnt anything to make a direct comparison to. Just like the Verado. Apples to apples deal.<br /><br />BRP does have a line of DI motors that can be compared to OptiMax and HPDI.

 

[tommays]

Re: Two Stroke vs Four Stroke?

if you look at the other big 4 stroke use which is motorcycles<br /><br />you have a good 25 years plus at this point of the valve train of Italian and Japanese haveing no problem running at over 9000 RPM and very happy at 5000 to 6000 all day long<br /><br />i thing the valves will neeed some adjustment but do have a track record of running at high RPM without a problem<br /><br />tommays