Two Stroke vs Four Stroke?

BillP

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Re: Two Stroke vs Four Stroke?

TheChad,<br /><br />All my 2 strokes (maybe 20+) have been carbed and the current Mariner (merc) 50 is a carbed 4 stroke...my former 2 stroke Mercs were from the 40s, 50s, 60s & 70s. Other than riding with friends who own late model Mercs (80s,90s,2001s)my personal experience is zero on the electronic fuel systems. <br /><br />Just like cars though, over the years you see design trends with each OB brand. Example: HP for HP, smaller Mercs always came with higher pitch props than OMCs. Merc powered boats were more sensitive to loading for speed. Run them light and they were faster, load the boat with people and the OMC was faster. As noted in previous messages, OMCs are more user friendly to work on, etc. The list goes on between the two.<br /><br />There are common denominators with ob electronic systems too...they are sensitive to low voltage. A local battery mfg (Royal Mfg) rep told me this is a VERY big deal at the marinas they stock (East coast). Let the batt get too low, the starter turns ok but the computer doesn't function right...and the motor won't start or run right. The fix is to keep the batt highly charged and batt mfgs are making larger capacity batteries JUST for this application. I don't see this happening with cars but it does with boats. That's another reason I would stay with carbs if going 4 stroke. <br /><br />What Dhadley said about corrosion...early Merc 50s 4s are widely known to have a corrosion problem where the water tube plugs into the powerhead. They used dismilar metals that attacked each other and plugged the water tube. Little details like that are what seems to plague mercs more than OMC. <br /><br />Again, what Dhadley says, the cost of working on 4 strokes is labor intensive compared to 2 strokes. Call your local dealer and ask what the cost of an annual checkup is for a 4 stroke vs same hp 2 stroke. Here's my numbers based on 9 yrs...$250-$300 for the 4 stroke and $75-100 for 2 strokes...same dealer. <br /><br />This is going to get people pizzed but IMHO...Most people who want to buy 4 strokes now are NOT going to listen to anything good about 2 strokes. They are NOT going to compare annual maintenance or major repair costs. They are NOT going to buy based on EPA data. They are NOT going to worry about "making water" in the crankcase, etc.. They ARE going to buy a 4 stroke because they perceive them better because someone said so.<br /><br />Remember guys, this is just MY opinion. I don't claim to be an expert...so don't get your panties up a crack.
 

TheChad

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May 29, 2005
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Re: Two Stroke vs Four Stroke?

My Only reason for still considering a 4-stroke is because i just moved from california where 2-strokes are beginning to be outlawed. Any drinking water lakes have already outlawed 2-strokes, both Carb'd and DFI, and ONLY allow 4-strokes to run.<br /><br />For that reason, I am cautious about buying any type of 2-stroke. I know they have not yet started regulating 2-stroke use here in IL, but if/when that time comes, I don't want to be buying another $8,000 engine! Also i want to be able to take my boat anywhere (Including other states) and not have to worry about if they allow the use of a 2-stroke.<br /><br />When I Purchase my boat, I want to make an engine selection and keep that engine till it wears out. My fauther had a 25hp Johnson 2-stroke (old type oil/gas mix in tank) That engine was probably 20 years old and never had any major problems.<br /><br />It seams like most people on this forum go threw engines like they go threw socks, but that is not what I plan on doing. I will only replace the engine when its time is up, so it is more key for me to find the right engine the first time.<br /><br />My consideration for a DFI engine is that atleast in the central United States I havent found any lakes that have outlawed 2-stroke engines all together, however i can easily see lakes in the future requiring 'Clean 2-Strokes', those of course being DFI's.<br /><br />That Said I have decided against the purchase of the 'standard' 2-stroke, and narrowed my options down to a DFI 2-Stroke, or a 4-stroke. If the DFI 2-stroke's were a fair amount cheaper then the 4-stroke's, then my choice would be alot easier, and I would just go with a DFI 2-Stroke, but since they are only a few hundred dollars cheaper then a 4-stroke, I am torn between them. Though the DFI 2-stroke is apealing to me because i wont have to worry about oil changes mainly, I can't see the 'constant maintaince' problems with 4-strokes that everyone keeps saying.. EVERY 4-stroke manufacturer claims LESS (Not Cheaper) maintaince with a 4-stroke, and in this case i would tend to agree with them. But Oil Changes would add up.<br /><br />-TheChad
 

BillP

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Re: Two Stroke vs Four Stroke?

2 strokes being outlawed is a darn good reason to buy a 4 stroke. I didn't think about that factor when posting earlier.<br /> <br />"Constant" maintenance to me is valve checking/adjusting and oil & filter changes...the book specs mine to be done every 100 hrs. That is a couple hours work I don't do on 2 strokes. Newer motors probably have higher thresholds and may use shims or hyd valves to ease the task.
 

JRJ

Commander
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Sep 11, 2001
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2,992
Re: Two Stroke vs Four Stroke?

4-strokers spend less on oil than 2-strokers.
 

TheChad

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Re: Two Stroke vs Four Stroke?

Originally posted by BillP:<br /> 2 strokes being outlawed is a darn good reason to buy a 4 stroke. I didn't think about that factor when posting earlier.<br /> <br />"Constant" maintenance to me is valve checking/adjusting and oil & filter changes...the book specs mine to be done every 100 hrs. That is a couple hours work I don't do on 2 strokes. Newer motors probably have higher thresholds and may use shims or hyd valves to ease the task.
Good point about the valves. Do you know when i could find what type of valves each manufacturer is using? I have looked on the specs pages, and none of them say the type of valves.<br /><br />I know just for example, My cousin has a Honda 400EX ATV, and it has to have valve adjustments, but i have a Suzuki Z400 ATV, and they use shims, and are never suppose to require a valve adjustment.<br /><br />So if any or all of the manufacturers are using Hydrolic or shim type valves as you mentioned, that takes one of the largest concers out of the picture.<br /><br />Thanks,<br /><br />-TheChad
 

umblecumbuz

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Sep 25, 2004
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Re: Two Stroke vs Four Stroke?

This thread is worth keeping. It's been a revelation to me. I work on motors and understand them, but getting a huge range of views is worth a lot.<br /><br />Often, people miss such points as the gear ratio when deciding on a motor, as Dhadley said. Or the simplicity of 2-strokes. <br /><br />I'll wait till there's more feedback on the promising E-tech range.<br /><br />Meantime, give me a good ole British Seagull!
 

swist

Senior Chief Petty Officer
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Jul 1, 2004
Messages
678
Re: Two Stroke vs Four Stroke?

Often, people miss such points as the gear ratio when deciding on a motor, as Dhadley said. Or the simplicity of 2-strokes.
Assuming that carbed 2-strokes are at the end of their lives and out of this discussion, I certainly wouldn't call DFI 2-strokes simple. Yes they have fewer moving parts in the power head itself, but the injection systems, very precision and operating at very high pressures, coupled with the computer etc to control it all, not only make the engine itself complicated but also make it complex to diagnose/service. Any auto mechanic or stern-drive mechanic can adapt to marine 4-stroke o/b's easily but DFI 2-strokes are a whole different world. If your DFI engine breaks the local all-purpose mechanic at your marina may not be able to deal with it without specialized training (which is different for each brand, since the systems have significant differences).
 

TheChad

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Re: Two Stroke vs Four Stroke?

That's a good Point swist.<br /><br />-TheChad
 

umblecumbuz

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Re: Two Stroke vs Four Stroke?

Yes they have fewer moving parts in the power head itself, but the injection systems, very precision and operating at very high pressures, coupled with the computer etc to control it all, not only make the engine itself complicated but also make it complex to diagnose/service.
Point taken. But similar computer-governed systems also run the four strokes, and I would not agree with the conclusion that any auto mechanic can diagnose electronic troubles more easily on a four stroke than on a two stroke.<br /><br />My son works on auto electronic trouble-shooting. That's four strokes exclusively. His comments on the foul-ups and bad programming that he comes across should not be repeated here, among maritime gentle folk!<br /><br />Conclusion? Four stroke electronic gremlins are every bit as difficult to fix as they are on two strokes.
 

BillP

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Re: Two Stroke vs Four Stroke?

TheChad,<br />Valves just wear slower when shims are used. They still need scheduled adjusting. The bad part about shims is the cost. They are too expensive to keep a supply of so you have to measure and then buy the right size. If you have a dealer do the adjusting make sure you keep shims that were replaced. Call a dealer and ask how much shims cost today. Back in the 80s I paid $7 each for Suzuki and Kawasaki shims. Sometimes it got rather expensive when doing 16 valve heads.<br /><br />I'm sure you local motor dealer can get details on valve types, etc. Also check if it has a timing belt or chain. The best to me would be shims and chain, just like motorcycles.
 

davejnz

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May 2, 2004
Messages
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Re: Two Stroke vs Four Stroke?

Originally posted by TheChad:<br /> I have been reading Spec's, and reviews, and Emmissions ratings. I have decided to either go with a Merc 90HP OptiMax, or a Evinrude 90HP E-Tec.<br /><br />Its going to be hard to decide which of the 2 i choose. I need to get pricing on the Evinrude, because if its far more expensive, then that will have a bearing on my choice.<br /><br />From the tests I have read, the OptiMax 90HP (2.33:1) seams to be faster by about 2-4 MPH then the E-Tec 90HP (2:1) on aprox the same size/weight boat. <br /><br />I Would like to have faith that 4-Strokes are not as bad as everyone keeps claiming, the only thing making me hold off of a 4-stroke is that they are a new technology to outboards, and I havent seen enough proof of their reliability (Then again I havent seen much proof of their in-reliability either)... Also the cost of Oil Changes...<br /><br />-TheChad
i guess it depends on whos doing the testing,according to this test,the E-Tec was faster test results
 

Sevcrist

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Joined
Apr 16, 2005
Messages
30
Re: Two Stroke vs Four Stroke?

From what I can see all of the boat motor manufacturers other than Bombardier are putting more and more 4 stroke EFI motors into their lineup of available motors. <br /><br />To me this says either more people are buying EFI 4 strokes and they are meeting that demand or the manufacturers see the future of boat motor technology as being EFI 4 stroke.
 

TheChad

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314
Re: Two Stroke vs Four Stroke?

Originally posted by davejnz:<br />
Originally posted by TheChad:<br /> I have been reading Spec's, and reviews, and Emmissions ratings. I have decided to either go with a Merc 90HP OptiMax, or a Evinrude 90HP E-Tec.<br /><br />Its going to be hard to decide which of the 2 i choose. I need to get pricing on the Evinrude, because if its far more expensive, then that will have a bearing on my choice.<br /><br />From the tests I have read, the OptiMax 90HP (2.33:1) seams to be faster by about 2-4 MPH then the E-Tec 90HP (2:1) on aprox the same size/weight boat. <br /><br />I Would like to have faith that 4-Strokes are not as bad as everyone keeps claiming, the only thing making me hold off of a 4-stroke is that they are a new technology to outboards, and I havent seen enough proof of their reliability (Then again I havent seen much proof of their in-reliability either)... Also the cost of Oil Changes...<br /><br />-TheChad
i guess it depends on whos doing the testing,according to this test,the E-Tec was faster test results
I guess you missed this part of the Review:<br /><br />"In our opinion, Mercury would have come out on top in the speed department if it had raised the engine one position."<br /><br />All the engine manufacturers used the 3rd hole, Mercury used the 2nd hole. (More Drag)<br /><br />-TheChad
 
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DJ

Guest
Re: Two Stroke vs Four Stroke?

My Only reason for still considering a 4-stroke is because i just moved from california where 2-strokes are beginning to be outlawed. Any drinking water lakes have already outlawed 2-strokes, both Carb'd and DFI, and ONLY allow 4-strokes to run.<br />
Typical California. "Let's pass a law and not know any of the facts". Many, if not all, DFI's are as clean or cleaner than four strokes.<br /><br />Again, typical California, the folks that brought us MTBE, the stuff that is REALLY poisoning their water supply. What a bunch of morons.<br /><br />I'd listen to what DHadley has to say. He's in the biz and has fixed more outboards than most of the people on this board have ever seen. A REAL pro. He doesn't offer opinions very often, when he does-I LISTEN.
 

TheChad

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May 29, 2005
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Re: Two Stroke vs Four Stroke?

Originally posted by DJ:<br />
My Only reason for still considering a 4-stroke is because i just moved from california where 2-strokes are beginning to be outlawed. Any drinking water lakes have already outlawed 2-strokes, both Carb'd and DFI, and ONLY allow 4-strokes to run.<br />
Typical California. "Let's pass a law and not know any of the facts". Many, if not all, DFI's are as clean or cleaner than four strokes.<br /><br />Again, typical California, the folks that brought us MTBE, the stuff that is REALLY poisoning their water supply. What a bunch of morons.
The Lakes that have banned 2-strokes, have banned them because they put oil in the water. They arn't concerned how much emissions are going in the air. A 2-stroke will ALWAYS burn oil, that's the nature of the beast. They have banned 2-strokes because they are drinking water reserves. To my knowledge, the Drinking water lakes are the only ones that have banned all 2-strokes.<br /><br />EPA and CARB care about emissions going into the air. The lakes care more about what is going into the water.<br /><br />-TheChad
 

davejnz

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May 2, 2004
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Re: Two Stroke vs Four Stroke?

yeah,but emissions still end up in the water via thru hub exhaust.
 

ziemann

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Re: Two Stroke vs Four Stroke?

The Chad-<br /><br />Even though I am a Nissan/ Tohatsu TLDI fan- truth is that the E-Tec's are the lowest emission outboard on the market. As much as it pains me to jump on E-Tec bandwagon (and support the rather vocal cheerleaders here). Yes a 2 stroke. <br /><br />Local governments tend to "knee-jerk" and cave in to out dated information presented by radical tree hugging lefties. *points toward California*<br /><br />I can see an arguement against old style 2 strokes- but often DFI 2 strokes are left out of the equation in favor of 4 strokes- when in reality DFI 2 strokes can meet or exceed the cleanliness of a 4 stroke. <br /><br />Davejnz is correct- it mostly goes through the hub- and that is taken into account.
 
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DJ

Guest
Re: Two Stroke vs Four Stroke?

MTBE is a heck of allot more harmful that what little oil a DFI emits.
 

Dhadley

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Feb 4, 2001
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16,978
Re: Two Stroke vs Four Stroke?

MTBE was, very quietly, removed from the fuel about 2001-2002.
 

pwiseman

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Re: Two Stroke vs Four Stroke?

Originally posted by Dhadley:<br /> MTBE was, very quietly, removed from the fuel about 2001-2002.
It is still in the water though. MTBE is nasty stuff.
 
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