Four Stroke vs Two Stroke

[StratosRob]

I know this has been posted before but just ran across a interesting artical.

I quote: The inherent inefficiencies of a 2 stroke outboards makes them less fuel efficient and costlier to operate tha a 4 stroke. Its becoming harder to find a carbureted 2 stoke in California those old 2 strokes have been banned for years and other states are considering similar bans. Lets say you want to move up to a bigger rig in a couple of years that old 2 stroke will be harder to unload on someone. The buyer may not be allowed to use that older outboard because of stricter EPA regulations.

From my understanding the new E-tec is cleaner and more fuel effcient than the four stroke. Just wondering if this raises any concerns ?

 

[JB]

Re: Four Stroke vs Two Stroke

Those concerns have been around for a few years, Rob. Hundreds of carbed 2 strokes have been destroyed in CA because they couldn't be sold.

Most of the Direct Injected 2 strokes are competitive with either carbed or EFI 4 strokes and all claim to be "cleaner". The ETECs are probably the best of them. The differences are in hair splitting territory.

Direct injected 4 strokes will be on the market soon. They will be even more economical and clean than today's engines, but still in hair splitting territory.

Machts nicht to me. I will be getting an EFI (or DFI) 4 stroke or an ETEC eventually.

The sad part is that today's carbed 2 strokes offer real advantages in the kicker size range and with good care can easily serve well for another 50 years. The only hope I can see for them is conversion to a clean burning fuel like alcohol/synthetic.

 

[StratosRob]

Re: Four Stroke vs Two Stroke

They still have'nt sold me on the 4 stroke. From what I read about the E-tec that would be the way for me. A guy told me one time that they layed all the parts of a 2 stroke on a table and then layed all the parts of a 4 stroke on the table. The 2 stroke had just a hand full of parts were as the 4 stroke parts would fill a 5 gallon bucket. The less moving parts the better I always heard. When it comes time to do a over haul or maint. on the 4 stroke you are going to pay out the butt. Im all for a cleaner burning engine just seems that they could do it with the 2 stroke. Guess you couyld say I dont like change.

 

[Silvertip]

Re: Four Stroke vs Two Stroke

Two strokes have not been banned from California or anywhere else. "Carbed" two strokes have been and that's a shame. Carbed two strokes when compared with the new four strokes at wide open throttle burn the same amount of fuel. Go to Yamahas web site and look at their performance reports. I have an Alumacraft Navigator 165CS with a 75 HP Merc two stroke (carbed). I also have a fuel flow monitor and it shows a flow rate of 8 gph with a full load of fuel, full fishing gear, two people and a full live well. It drops to 5.2 at 4200 RPM. A 75 Yamaha 4S on the same boat at WOT show 7.7 GPH. A 70 Yamaha 2S on a similar boat shows 7.4 GPH (but it is much smaller displacement). So There you are. These are fuel flow monitor and manufacturer values. It is only in the mid and low speed ranges where the 4S has an advantage over a carbed engine. I too am not convinced 4S is the way to go. I recently visited a shop that had 18 4S blocks laying on the floor, all with holes in the side where a rod came through. When I questioned the shop owner, I was hustled out of the shop and did not get an answer. I did see one old two stroke in the corner that dated from the 60's (and it probably still ran).

 

[steelespike]

Re: Four Stroke vs Two Stroke

Too many moving parts in a 4 stroke.
1 power stroke in 4 strokes
1 power stroke in 2 strokes with a 2 stroke.
Etec is presently the cleanest burning outboard period.
In my opinion the future is in etec and similar 2 strokes.

 

[rickdb1boat]

Re: Four Stroke vs Two Stroke

I think the bans are due to EPA concerns over unburned fuel/oil being tossed into the lakes. The older 2-strokes are not the most efficient beasts out there as far as complete combustion is concerned. If it was just a matter of fuel consumption, I don't think there would be such a stink...

 

[JRJ]

Re: Four Stroke vs Two Stroke

Check the rental fleets and get the mechanics opinions of whatever OB you are interested in.

 

[jethro66]

Re: Four Stroke vs Two Stroke

You save money on oil with 4 strokes so it goes to gas. just to get off topic I tried the new yamaha 4 stroke fuel injected snowmobile last winter and I just loved the power and that lovely exhast note. I traded in my old 2 stroke.4stroke is here to stay .BRP is to much money

 

[Chunder06]

Re: Four Stroke vs Two Stroke

Obviously you havn't done the sums Jethro, oil filters , oil, timing belts, multiple services all add up, none of these charges with the E-Tec, as for oil they use very little all controlled by computer, no dealer service for 3 years or 300 hours....how many times in 300 hours does a Yammie require a service. Do the sums old son, you might be a convert...I was.d

 

[rodbolt]

Re: Four Stroke vs Two Stroke

that E-tec 3 year service schedule is based on 50 hours a year of use, at 50 hours a year that yammie could go the distance with ease. how ever to many folks are just gonna neglect it till it breaks then whine.
however I just ordered a 175 E-tec so I can see if it will break.
I told the dealer,a long time friend, I was gonna break his motor .
Ron said no worries ya got 3 years of warrenty.
I just hope it puts my 18ft hydra sports in the low 70's anyway
most the 4 stroke failures I have seen were customer induced just like most all the two stroke failures were so not much has changed.
the only odd thing we have seen with the four strokes so far is the piston rings tend to rotate and the gaps will line up and it will start "making" oil.
I hope one day they will pin the ringslike a two stroke and eliminate that as an issue.
we have found that if you get water in the fuel and stick an exhaust valve on a V6 it will set you back about 7500 dollars.
by the same token I am replacing 2 200 HPDI and 2 Z300 HPDI powerheads due to water in the oil. costs just over 16,000 dollars for each pair.
all of the above failures,except the ring issue, were customer induced.
water in the fuel or oil IS NOT a warrenty issue.

 

[StratosRob]

Re: Four Stroke vs Two Stroke

Seems there are more pros thans cons on the E tec
2 STROKE From every thing I've read and heard I think my next motor will be the E tec. Well what I was told about the repair bill for the 4 stroke turns out to be right.$$$$

 

[edgutgesell]

Re: Four Stroke vs Two Stroke

4 stroke engines are too heavy, too many parts, and not more fuel/oil efficient than a Etec. I really like my old 150 Yamaha. I have had some problems with it, but all-in-all it has been the best outboard I have ever had and I have had a few. I hope Yamaha comes out with a 2-stroke like the Etec. If Yamaha doesn't, it will be Etec for me next!!!

 

[JB]

Re: Four Stroke vs Two Stroke

With modern auto engines (from which most 4 stroke outboards are developed) routinely going 200,000 miles (equivalent of around 5,000 hours) I find the myth about "too many parts" hard to swallow. They work, and they work well.

Compare the weight of 4 stroke EFI engines with their DFI 2 stroke and even ETEC equivalents and that story deflates a lot, too.

Compare the prices of DFI 2 strokes with EFI 4 strokes of the same hp.

What are the significant differences? Preferences based on emotions. . . like Ford vs. Chebby.

No need to invent (or parrot) obective-sounding mythology. Just say what you prefer and let it go at that.

 

[swist]

Re: Four Stroke vs Two Stroke

Right on JB. For one thing, parts count is a poor predictor of reliability unless you do a lot more scientific analysis. And the level of complexity between DFI 2-strokes and EFI 4-strokes is pretty comparable.

 

[jethro66]

Re: Four Stroke vs Two Stroke

Theres snow in tasmania?

 

[Chunder06]

Re: Four Stroke vs Two Stroke

We are just coming of a low snow winter, lake level down, the main land has droughts and high fire danger and its only spring.8)

 

[steelespike]

Re: Four Stroke vs Two Stroke

With modern auto engines (from which most 4 stroke outboards are developed) routinely going 200,000 miles (equivalent of around 5,000 hours) I find the myth about "too many parts" hard to swallow. They work, and they work well.

Compare the weight of 4 stroke EFI engines with their DFI 2 stroke and even ETEC equivalents and that story deflates a lot, too.

Compare the prices of DFI 2 strokes with EFI 4 strokes of the same hp.

What are the significant differences? Preferences based on emotions. . . like Ford vs. Chebby.

No need to invent (or parrot) obective-sounding mythology. Just say what you prefer and let it go at that.

You seldom run a car uphill in 2nd gear at 5,500 rpm for mile after mile.I think you will find a 4 strokje powerhead
rebuild is more costly than a 2 stroke and is rerquired more often.Then there is valve adj. timing belt replacement,oil changes.
I don't have a clue but I wonder how many hours a 100,000 dollar stock car engine is good for.3 hours?

 

[JRJ]

Re: Four Stroke vs Two Stroke

The lack of problems with EFI 4-strokes on these forums should be a clue to the uninformed? Or not8) If ring-a-ding sounds good and smells good to you, then buy one. If re-sale matters to you then guess what used boat buyers are after8) Enjoy whatever you get

 

[Lundman]

Re: Four Stroke vs Two Stroke

Being new to the site,I would like to put my two,or three,
cents in. I am considering purchase of a 2007 Sylvan
Sport Troller 1600 aluminum boat,and would rather power it with an E-TEC Evinrude two stroke motor,but the salesman is trying to talk me out of the E-TEC for
reasons such as high oil consumption,low fuel economy
compared to 4 stroke,and noise. Like the rest of you,I am not convinced 4 stroke is the way to go because of the overall expense to have them serviced,oil filters,oil
changes,valve adjustments,etc. Besides, with past prob-
lems with Mercury,I don't have much confidence in that
brand at all. The salesman is trying to get me to go with
an EFI Merc 4 stroke,but I don't want to. Afterall,I am the
one buying the boat,...not him.:/

 

[cobra 3.0]

Re: Four Stroke vs Two Stroke

He'll sell you where he has the best deal...for himself. None of his statements on the Etech are true.

Merc is part of the Brunswick Corporation's ALMOST monopoly of the boating industry.