4 Stroke OB's Rebuilding Questions

Dhadley

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Since the 4 stroke outboards have been out a while now, are there any being rebuilt? If so, which ones? And why (sinking, no oil, worn etc)? How many hours are they getting before needing major work?<br /><br />I know.... too many questions!
 

enn

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Re: 4 Stroke OB's Rebuilding Questions

I just rebuilt a 75 hp Honda - due to it had been sunk and started up with water in the oil (and ran with that "lubrication" for a couple of hours.<br /><br />It was not rebuild due to normal wear.
 

enn

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Re: 4 Stroke OB's Rebuilding Questions

BTW<br /><br />I know of several Suzuki and Honda 4 strokes that have more than 3500 hours on them - still they run strong.<br />4 Strokes have superior (compared to 2 strokes) lubrication and they should outlive most 2 strokes.
 

clanton

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Re: 4 Stroke OB's Rebuilding Questions

I seen 3 heads off of Suz at machine shop that were being welded, had cracks from headgasket surface to water jacket. I ask machinest if the weld would hold, he said hope so, new head cost a lot.
 

steelespike

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Re: 4 Stroke OB's Rebuilding Questions

My own personal opinion.There is some great 4 <br />stroke technology out there but.There are just too many moving parts.Very difficult to have favorable power to weight ratio.Keeping in mind all expenses I dont think the 4stroke is any better than 2 stroke at saving money.2 stroke<br />moving parts 1crank,2rod,3piston 4.reed valves..4 stroke moving parts.1.crank,2.rod,3piston,4camshaft5.cam gear,chain or belt,6.cam follower(2per cylinder)7.Valves(2per cylinder)8.valve springs(2 per cylinder)9.lets lump all the various keepers spacers etc. under one number.<br /> Is it any wonder a 4 stroke usually weighs more<br />than a 2 stroke. <br />Im showing my age but if I bought a new motor<br />today it would be a 2stroke.
 
D

DJ

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Re: 4 Stroke OB's Rebuilding Questions

enn,<br /><br />I disagree with your analogy that 4's have superior lubrication over a 2.<br /><br />A 2-stroke by its very nature has superior lubrication. Every square inch of a 2-stroke's crankcase is lubricated. Not so with a four.<br /><br />Two strokes only lack for lube when a carb. malfunctions and the fuel/oil mixture doesn't get past the reeds-or when someone forgets to put the oil in.
 

clanton

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Re: 4 Stroke OB's Rebuilding Questions

Suz used to build a 3 cylinder water cooled motorcycle that had a perssure fed crank and rod bearings just like a four stroke. I like them both 2 and 4 stroke, and I hope the 2 strokes stay around a long time. Overhead cam 4 stroke very old technology and soneone should be able to build one that gets very close to weight and power of the 2 stroke.
 

Dhadley

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Re: 4 Stroke OB's Rebuilding Questions

I was wondering why we dont see very many of these being rebuilt. I understand they are reliable but people still sink boats and let motors run out of oil, etc.<br /><br />Are parts (pistons, gaskets, bearings etc) hard to come by? Expense? Or is it shops are not willing to take on the job?
 

hondon

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Re: 4 Stroke OB's Rebuilding Questions

Had the honor of rebuilding a couple Hondas. One from poor propping[lugging severely] ,others from water ingestion one way or another. Rebuild is not much more tedious than a two stroke and comparable to a small version of a sterndrive rebuild.Plastigage the bearings etc..As the years progress you can bet we'll see more of it.
 

enn

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Re: 4 Stroke OB's Rebuilding Questions

To djohns19 <br />4 strokes have pressure lubrication - 2 strokes have not.<br />The 2 stroke bearings (roller/ball) are not a good solution for a combustion engine this is basic engineering knowledge<br /><br />As EPA 2006 etc. starts to get implemented the 2 strokes are squezed on oil to comply with exhaust regulations.<br /><br />I love my 2 strokes - but the 4 strokes are better engines IMHO
 

terryc

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Re: 4 Stroke OB's Rebuilding Questions

Considering that max H.P is only acheived at max Rev's, How long could you run a four stroke at maximum rev's for. I've read of guys running 2 strokes at max rev's for a number of hours. :rolleyes:
 

Franki

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Re: 4 Stroke OB's Rebuilding Questions

enn, <br /><br />I'd like to discuss this...<br /><br />According to the epa stats, the 2001 Evinrude 225HP Ficht has alot LESS (18%) emmisions then a yammy 2002 4 stroke...and is in fact ALREADY putting out less then half the emmisions that the 2006 EPA rules specify it also puts out 240HP and weights 100 Pounds less then a yammy four stroke.<br /><br />And the best bit, it uses significantly less fuel, (again about 18% less.) then the yammy four stroke. <br /><br />And it revs happily to over 6000rpm....<br /><br />which brings me to my next point, roller bearings.<br /><br />my RM250 motorcross bike was a 2 stroke with roller bearings.. and it redlined at 11,000RPM.<br /><br />I never had to replace the big end bearings in all the time I raced that bike.. through several pistons, god knows how many ring sets, but the bearings never had a problem..<br /><br />That thing was worked to the eyeballs, custom pipe, forged piston, port and head work, boyseen reeds etc etc.. the engine coped a hammering and very very high rpms, and yet I never had a problem with the bearings.<br /><br />As a result of that, I don't believe what they say about roller bearings not being as good..<br /><br />I do believe that roller bearings would be very hard to use for positive presure lube systems like in a four stroke.. (since you'd lose a ton of pressure at each bearing.) but that doesn't make the bearing bad. they are also harder to fit.. then shell type bearings, but again that doesnt' make them worse.. and the quality of material in these things is far superior to what it used to be.<br /><br />just some more comments..<br /><br />I like both 2 and 4 strokes.. would have either.. but if you are going to say one is better then the other, prove it with current stats.... so far the ficht is the clear winner by a pretty good margin. and now that they are run by the quality control maniacs (Bombardier) they will advance quickly.<br /><br />keep and open mind and ye will go far. :) <br /><br />rgds<br /><br />Frank
 

Dhadley

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Re: 4 Stroke OB's Rebuilding Questions

Hondon -- On the couple you rebuilt, were the parts hard to come by (avalibility)? Did you have to bore them? What horsepower motors were they?<br /><br />Thanks!
 

enn

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Re: 4 Stroke OB's Rebuilding Questions

Hello Frank,<br /><br />roller bearings have a shorter lifespan than glide bearings (i calculated on them often app 15 years ago when designing MAN B&W engines)<br /><br />Roller bearings and needle bearings have a wery little contact surface to transmit pressure - glide bearings have a large surface.<br /><br />Roller bearings and Needle bearings do not like pulsating forces like the ones in a Piston engine.<br /><br />2 cycle OBs only get lubricated by oil in the fuel - or by small drops of oil from the Oil injection system.<br /><br />4 stroke with pressure feeded lubrication get a steady stream of oil - and the oil also cools surfaces in the engine.<br /><br />The FICHT is today an ok system - but the emissions level it acheves with this sufisticated direct injection system is not better that on a simple indirect MPI 4 stroke engine. Direct fuel injection can (and will) be implemented on 4 stroke OBs (like the Mitsubishi GDI engine) and that will put it in front of the Ficht.<br /><br />FICHT has by the way a bad reputation here in Europe - OMC/Bombardier left us stranded with no upgrades no service etc - dont think they will get any marketshare for a long while.
 

Franki

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Re: 4 Stroke OB's Rebuilding Questions

Ok, I'll not argue the ficht issue, its a moot point really. Who knows what DFI will do for 4 strokes.. there is stuff you can speculate for both types.. this should be based on current performance statistics. and the ficht wins.. and the Optimax was right up there too..<br /><br />but I will say this.. As has been pointed out on this list time after time.. most outboards never reach the end of their lifespan from simple wear.. most are from owner error or manufacturing fault.<br /><br />In this application, roller bearings failing is very very rair compared to the other things that kill outboards, so the comparision is not really valid.. can anyone here say they have had many cases where roller bearings have been the reason for a rebuild or replace. ??? more often then not is a piston that detonated or something similiar. Wether or not rollers are better or not is a moot point, they have been used on outboards for more then 40 years, many of which are still around now.. Its obvious they last perfectly well in this application.. most people who would by a Ficht now, wouldn't be likely to keep it for 30 years anyway. So bearings aside, longgevity aside.. (2 strokes have proven that as well.. all you can quesion is the DFI system and that goes for 4 strokes as well.) <br /><br />So at the end of the day, compare the current best of breeds from each time and compare then,, leave brand history out of it, and preference.. <br /><br />Whats the current best performing 4 stroke on the market? suzi or yam? or maybe honda? dunno.. <br /><br />but if we compare it to the best two stroke on the market now as well, (the ficht I think, but I guess thats open for discussion as well.) and compare then completely evenly..<br /><br />If they two were on identical boats, and you had to bet $1000 of your hard earned dollars on which one would get the boat to top speed fastest.. what would you put your money on? the four stroke or the ficht?<br /><br />After reading the stats.. would you put that 1000 dollars on the 4 stroke for emissions or ecommony as well?? (keep in mind that the EPA have already declared the winner on that too.)<br /><br />There is no DFI 4 stroke on the market yet.. when there is, then we can compare again.. but right now, the 2 strokes win.<br /><br />if you compare apples to apples with what exists today. the 2 stroke ficht is the winner hands down..<br /><br />I'll be the first to admit it if that changes.. I have no preference, but I get really annoyed by blanket statements that say one is better then the other and I always stick up for the underdog (if its justified. :)<br /><br />There is alot of 2 stroke bashing on this list whenever the subject comes up, and it annoyes me because people use reasons that have been proven false for outboards.. (like the roller bearings).<br /><br />The simple point of the matter is this.. right now, there is no cheaper way to get that sort of power and ecconomy on the back of your boat rigth now then with a DFI 2 stroke. End of story.<br /><br />regards<br /><br />Frank
 

Franki

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Re: 4 Stroke OB's Rebuilding Questions

I forgot, I wanted to comment on your statement:<br /><br /><quote><br />The FICHT is today an ok system - but the emissions level it acheves with this sufisticated direct injection system is not better that on a simple indirect MPI 4 stroke engine. Direct fuel injection can (and will) be implemented on 4 stroke OBs (like the Mitsubishi GDI engine) and that will put it in front of the Ficht. </quote><br /><br />Thats simply not true, as the epa stats showed, it made a 2 STROKE 18% better on emisions then one of the best performing four stokes..<br /><br />I don't think adding DFI to four strokes will make as huge a difference to the fours since the system isn't that inefficient now (compared to say efi on a 2 stroke.)<br /><br />Who knows, it might even the score.. what happens then?<br /><br />I can think of a dozen ideas that could improve 2 and 4 strokes, but until it happens, I'll say it again, compare the current best of breed evenly and fairly on all criteria and then form your opinion. I am not one to toe the popular line if it doesn't make sense.<br /><br />rgds<br /><br />Frank
 

enn

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Re: 4 Stroke OB's Rebuilding Questions

Hello again Frank,<br /><br />I think there are more issues to the 2/4 stroke story than top speed weight etc.<br /><br />I was one of the few here in Europa that had a Homelite 4 stroke (still has it) and I have had many OBs what is most important for me today is low noice, smooth runing etc. today (i am 37) it is not so important if I go 35 or 37 knots -but that is up to everyone of us to decide for our selve.<br /><br />I love the 4 stroke - and i realy love my 15 hp Evinrude 2 stroke - it is fast and light - my 4 strokes (a 30 hp Suz, a not running Homelite 55 hp and a 75 hp Honda) is quite and smooth runing - both types have their advantage - but I think the 4 stroke will be the winner in the long run - 4 strokes can be run with catalytic converters - that is a problem with 2 strokes (due to unburnt oil etc.)<br /><br />As I have already written i like both OB types - and i agree about that most OBs die from corosion and neglect not from runing hours (I have only experienced that once with my first OB a Joh. 3 hp JW-17 that i simply wore completely out - but that is an old story)
 

Franki

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Re: 4 Stroke OB's Rebuilding Questions

Well mr enn,<br />Its been lovely discussing this with you, lets agree that they both have their place.. and that since I have owned neither a 2002 ficht, or a 2002 yammy of other modern efi 4 stroke, I am not ably to really comment on either with regards to personal experiance.. I have been on boats with efi four strokes, and I was impressed.. I have been on boats with older fichts.. and I was also impressed.. both seemed far quieter, smooter and easier to start then my old 100HP Jonny that I have now. (which I've gotten attached to now.)<br /><br />Who knows where things will go?<br /><br />I think its quiet possibly to make a 2 stroke with the same sump as a four stroke.. (I read somewhere that its actually been done.) that would certainly even thing out abit too wouldn't it? <br />In another post on this board I speculated what would happen if you replaced crank case compression with a mild boost Whipple supercharger, which would ram the air straight into the cylinder.. it could be done, and it would be a whole new ball game.. and the race starts again.. its all good news as far as we are concerned.. <br /><br />I love motors, I don't care what they are... :)<br /><br />rgds<br /><br />Frank
 

enn

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Re: 4 Stroke OB's Rebuilding Questions

If you look at larger 2 strokes like the MAN B&W 2 stroke ship(and power plants) engines of up to 100.000 HP you will se that they have pressure lubrication in a closed crankcase - the scarving air (spelled right?) comes from the TC via a Charge air reciever directly to the intake ports in the cylinders - the exhaust passes tru a outlet valve (controlled by a camshaft lifter etc.) in the cylinder head.<br /><br />It is possible to make the same system on an OB - but i guess it will make it as heavy as a 4 stroke.<br /><br />Have a nice summer.
 
Joined
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Re: 4 Stroke OB's Rebuilding Questions

hello,enn<br /><br />can you explain a little more why you think omc/bombardier has left you stranded with no upgrades or service.
 
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