Outboard Engines: Rebuild or Buy New

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
jimh
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Outboard Engines: Rebuild or Buy New

Postby jimh » Tue Nov 14, 2017 11:26 pm

A fellow asked for my opinion on whether he should undertake the rebuild of c.2001 OMC 70-HP twin engines for his Boston Whaler OUTRAGE 18 or GUARDIAN type boat at a cost of about $7,000, or, alternatively, buy a new 150-HP engine to replace the 16-year-old twin engines. I offered my stock reply, which I think applies to just about any decision to hire out the labor of rebuilding an outboard engine:

My thinking on undertaking a rebuilding of an older two-stroke-power-cycle outboard engine: you really are putting all your faith into the skill of the rebuilder. If the person you hire to perform the rebuild is really an expert, really a craftsman, really has done this before with excellent outcomes, then maybe you get a rebuilt engine that is like new. The outcome is really in his hands. Also, what components does he use for replacements if something needs replacing? Does he get the top-grade, best possible replacement parts? Used parts from a donor engine? You need to have a lot of faith in the rebuilder.

At one time there were probably several firms or places or individuals that possessed this kind of skill; such vendors could offer a valuable service. I suspect that two things have happened in the last 15-years: all the skilled artisans who were able to rebuild classic two-stroke-power-cycle engines are now 15-years older than they were, and are probably at retirement age; and, the market demand for rebuilding classic two-stroke-power-cycle engine is probably much lower than it was 15-years ago, tending to drive suppliers out of that business.

As for going with a new, single, modern 150-HP engine, that is probably a good idea. Here I am spending someone else's money, so I don't care if it costs a lot more than rebuilding. A modern engine will be a surprise to many who haven't owned one before: a modern outboard engine starts easily, runs smoothly, has much lower sound signature, and does not need a lot of repair or maintenance. It will use less fuel, need less fuss, and produce less smoke and exhaust gas emissions.

Now, having just said all that, there are people who really like classic two-stroke engines, and if a great rebuilder still exists to work with, then consider having the engines rebuilt. There is something cool about starting up a vintage engine, having it run well, and keeping it running. And the amount of extra fuel you burn won't ever be as much expense as a new modern engine--you'll be money ahead.

msirof2001
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Re: Outboard Engines: Rebuilt or Buy New

Postby msirof2001 » Wed Nov 15, 2017 10:00 am

My principal reason for moving away from the older two-stroke-power-cycle outboard engine was the heavy smelly smoke it generated. A major part of the time I spend on the water is fishing. When fishing and not anchored, the drag created by the lower unit and propeller in the water would cause the boat to drift such that the motor is always facing the wind and smoke is blowing back over the length of the boat into my face, coating my lungs. We are never standing still long enough to turn the motor off and on at every stop. Plus there is always the risk that one time it won't turn back on. My memories were of that blue/gray heavy smoke and smell and the noticeable feeling in my lungs. There is no escaping the smoke given the small footprint size of a boat. The newer four-stroke-power-cycle outboard engines don't affect me as much in this regard.
Current: 2017 Everglades 295cc, Previous1: 1995 Boston Whaler Outrage 21, Previous2: 1974 Sevylor Caravelle 3-man liferaft.

dtmackey
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Re: Outboard Engines: Rebuild or Buy New

Postby dtmackey » Fri Nov 17, 2017 11:29 am

The actual rebuild process for a 2 stroke is relatively simple and the parts are reasonable if you have access to dealer costs. I say this after having run a marine business and rebuilding lots of 2 stroke motors. There isn't much to it and the biggest challenge is corroded fasteners. This is a blanket statement and it does some down to the brand and model of older motor as some were poor designs and not worth a rebuild, yet others will stand the test of time and seem to run forever.

Some people are willing to overlook the additional fuel burn and two-stroke smoke and in return have a simple to work on and lighter engine that comparable DI or 4 stroke technologies cannot offer today. While I love the Etec 250 on my center console and would not choose and older technology, I also appreciate the two stroke motors currently owned - 5 Tohatsu, 15 Yamaha, 25 Yamaha and 70 Yamaha and many people actually prefer 2 stroke in the smaller outboard sizes for a number of reasons:

- Weight savings (significant)
- Carbs less prone to gumming up over 4 stroke
- Very simple to work on
- Proven designs with many years of production
- Not sensitive to storage position (leaking oil from 4 strokes)
- Higher torque values available at lower RPMs in same HP ratings
- Lower maint - no oil changes, no valve adjustments

Weight as a comparison:
85# 15 Yamaha 2 stroke
111# 15 Yamaha 4 stroke

108# 25 Yamaha 2 stroke
181# 25 Yamaha 4 stroke

D-

pcrussell50
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Re: Outboard Engines: Rebuild or Buy New

Postby pcrussell50 » Sun Jan 07, 2018 3:46 pm

The weight difference is not just a matter of elegance (less weight for more power is always more elegant than the other way around), it also matters for us owners of classic Whalers, where the weights of today's engines were unheard of back when our boats were designed. A 400-lbs 90-HP engine on the transom of a classic Montauk is obscene. Some savvy Whaler owners (and CWW members) had the gumption to re-power with 75-HP four-stroke-cycle engines to cut off a little of the crazy weight. But at a price: smaller displacement means less torque, and the four-stroke-cycle compared to the two-stroke cycle means even less still.

Not to mention, and it's hard to imagine in boating, but if green is your thing, re-building is fa-a-a-r greener and more socially responsible than discarding-and-then-contributing to a market for all the wasted resources it takes to create something new--even after accounting for newer technology's less visible emission (smoke), and lower fuel burn at part throttle. You'll never save enough fuel or emissions to make up for the increased cost of buying something new or to make up for the resources used and pollution incurred from the development and production of a new motor from scratch.

And of course, smoke is isn't nearly as bad as carbon monoxide just because you can see it, and fuel burn at planing speeds and loads is not very different from old to new.

-Peter

msirof2001
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Re: Outboard Engines: Rebuild or Buy New

Postby msirof2001 » Tue Jan 09, 2018 11:33 pm

pcrussell50 wrote:Not to mention, and it's hard to imagine in boating, but if green is your thing, re-building is fa-a-a-r greener and more socially responsible than discarding-and-then-contributing to a market for all the wasted resources it takes to create something new--even after accounting for newer technology's less visible emission (smoke), and lower fuel burn at part throttle. You'll never save enough fuel or emissions to make up for the increased cost of buying something new or to make up for the resources used and pollution incurred from the development and production of a new motor from scratch.

And of course, smoke is isn't nearly as bad as carbon monoxide just because you can see it, and fuel burn at planing speeds and loads is not very different from old to new.

-Peter

I remember in the late 1990's going through Newport Harbor, Newport Beach, CA when all of the boats were two-cycle, and there was a smell of smoke at all times. It was quite heavy. I don't think that was good for the environment. Also, I think two-cycle and four-cycle engines would both put out Carbon Monoxide. I would suspect that the amount of carbon monoxide output would parallel the amount of fuel burned (if there are any scientists out there who feel I'm wrong, please correct me). If you have an older two-cycle engine like my old 1995 Yamaha 200TXRT that got me 2.25 miles per gallon, and compared it with the Yamaha F200 XB four-cycle which got me over 4 miles per gallon, I would think I would almost double the amount of exhaust per mile, and double the carbon monoxide. And on top of that, add the smoke/exhaust differential for burning two-cycle oil mixed into the fuel. I would think that after prolonged use, there would be an offset, albeit apples-to-oranges comparison, with the air pollution of the two-cycle differential compared to the carbon footprint of disposing, net of recycling, and manufacturing the new four-cycle engine. Not to mention the jobs involved, etc.
Current: 2017 Everglades 295cc, Previous1: 1995 Boston Whaler Outrage 21, Previous2: 1974 Sevylor Caravelle 3-man liferaft.

Shickalee
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Re: Outboard Engines: Rebuild or Buy New

Postby Shickalee » Sun Jan 14, 2018 5:43 pm

My recommendation would be an ETEC 150, the weight is as low as 418lbs for a 1st Gen, the twin 70's are closer to 500lbs. On the ETEC go 2008 and above as that is the year when the fuel injectors were standardized. There is seller on ebay offering for ETEC 150's for approx $7,500 with a 1yr powerhead warranty.

Shickalee
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Re: Outboard Engines: Rebuild or Buy New

Postby Shickalee » Sun Jan 14, 2018 5:47 pm

I have had 2 strokes the past 15 years. They smoked at first start-up, but, while running the rest of day and starting and stopping, there is no noticeable smoke. They are louder all the time while running than an E-TEC or four-stroke and burn more fuel, but they are easier and cheaper to maintain.

pcrussell50
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Re: Outboard Engines: Rebuild or Buy New

Postby pcrussell50 » Sun Jan 14, 2018 6:12 pm

Shickalee wrote:I have had 2 strokes the past 15 years plus, mine smoke at first start up but while running the rest of day, start and stop there is no noticeable smoke but they are louder all the time while running than an ETEC or 4 stroke and burn more fuel but they are easier and cheaper to maintain.


All perfectly true. And even with the greater fuel burn, you will never get your money back versus buying new, AND if green is your thing you will never make back the immense “carbon cost” or the enormous natural resources and energy expended in the creation of a new motor. Some people think that because their expensive new motor uses less fuel, that it’s somehow greener. Nothing is further from the truth, and nothing is greener than continued service of resource-intensive machinery. Another misattribution of pollution is smoke. I think a lot of people mark it as a bogeyman because you can see it. Well carbon monoxide is faaar worse, and you can’t see it or smell it. Visibility is NOT the definitive mark of toxicity. Not that older motors don’t make more CO... they probably do. It’s just a sign of ignorance to make smoke your bogeyman IF you are standing on a green pedestal. Now, if you simply don’t like the look or smell of it, that’s quite another thing. It’s up to you and your vanity to decide if it’s worth the large expenditures it takes to reduce it for the times you are going slow enough for it to exist and for you to have to see it.

In short, if you want a new motor good on you. Revel in its goodness. I would. But don’t use greenness as your aid to help you sleep at night. You are only fooling yourself. No need for that. You can and should rejoice in its goodness for what it is. No need to seek false justification.

-Peter

Whal
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Re: Outboard Engines: Rebuild or Buy New

Postby Whal » Tue Jan 16, 2018 7:29 am

In my case I had a 2005 Mercury 75-HP two-stroke-power-cycle outboard engine. I re-powered with a 2014 Yamaha F70. I liked my Mercury 75, and it ran great; but it seemed that every summer something would happen to it, and I would be waiting a couple of weeks for parts and repair. The engine ran fine but components were the problem, such as the swivel pin and oil tank. These repairs not only cost time they cost money, it seemed I was putting more money in this engine every year.

I finally decided to re-power with the Yamaha F70, and I love it. The Yamaha F70 starts easily, runs quietly, and I use less than half the fuel that I used with the Mercury75. My point: even when you rebuild the engine there are still a lot of old components on it that could fail; with a new engine every part is new.

In my case and in the 70 to 70-HP range, to re-power made sense to me. If I had to buy a 150-HP engine I might rethink that move; but in my case [re-power] was a good move because all I have had to do to the new engine is put fuel in it and do routine maintenance. I do miss the smell of that two-cycle smoke in the morning, and sometimes I have to fire up my chainsaw to get a fix.

jimh
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Re: Outboard Engines: Rebuild or Buy New

Postby jimh » Fri Jan 19, 2018 9:39 am

About 50-years from now, a c.1970 Evinrude two-stroke gasoline engine with a carburetor will still be running. I wonder how many c.2010 Evinrude E-TEC engines will still be running.

pcrussell50
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Re: Outboard Engines: Rebuild or Buy New

Postby pcrussell50 » Fri Jan 19, 2018 11:20 am

jimh wrote:About 50-years from now, a c.1970 Evinrude two-stroke gasoline engine with a carburetor will still be running. I wonder how many c.2010 Evinrude E-TEC engines will still be running.


This is not lost on third world fishermen, where feeding your family takes precedence over the vanity and luxury of less smoke or noise, and even the high cost of petrol is not enough economic justification to spend what it takes for a more luxurious and fuel efficient motor.

We spent July of 2016 in a fishing village Mexico. I brought my 1985 13 Sport with same year carbureted Yamaha 40. To the Mexicans, that was a dream motor. I was a minor celebrity at the marina. My FIL brought his center console Striper with the same modern direct injection Evinrude as all the other gringos. It was invisible to the locals.

-Peter

Jefecinco
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Re: Outboard Engines: Rebuild or Buy New

Postby Jefecinco » Fri Jan 19, 2018 7:37 pm

I've only owned one outboard engine for more than 10 years. It was a 1999 115 HP Evinrude FICHT the predecessor to the current ETec series. The engine was never repaired. The only maintenance items replaced were spark plugs and water pump impellers. That leads me to believe the Evinrude DI engines are extremely reliable. The only reason the Mexicans don't want one is that they lack the technological ability to keep them running. Duct tape and baling wire just don't get the job done with modern engines. Carbureted engines are easy to keep running, especially if premix fuel is used. The internal engine parts are child's play to the typical Mexican mechanic raised on the concept of keeping things running with only the basic tools and very few new parts.
Butch