Johnson 90-HP Older v. Newer

Optimizing the performance of Boston Whaler boats
medic one
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Johnson 90-HP Older v. Newer

Postby medic one » Thu Feb 25, 2016 12:47 pm

I have a 1994 Johnson 70-HP on my 15' Super Sport. I find it easy to work on, with readily available parts. After a few maintenance procedures it is running strong!

I am now shopping for a used outboard for a vintage 20-foot fiberglass runabout. Having experience with the Johnson-OMC I'm looking to stay in that family. I'm looking at a 1993 (for $2,000) and 2003 (for $3,000) Johnson 90hp V4. The 1993 I assume to be a crossflow and the 2003 to be a looper. The 2003 uses optical ignition. I'm sure there are other differences as well.

By spending $1,000 more for a 10-year-newer engine, am I getting significant improvement? Or, is the simplicity of the 1993 a better value? The 1993 was rebuilt a couple of years ago.

I've read so many posts about the reliability and simplicity of the older motors. If a guy can find an older motor that has been well cared for, is that the right course?

Or, is newer but still-a-carburetor two-stroke-cycle engine a more prudent path?

Thanks for the thoughts.

jimh
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Re: Older vs Newer Johnson 90hp

Postby jimh » Thu Feb 25, 2016 4:25 pm

I'd lean toward the 2003 model OMC engine for these reasons:

--the 2003 is ten years newer, hence only 13-years old; the 1993 engine is getting to be an old engine, now 23-years-old. At that age you can expect to have problems with anything in the engine that is rubber and touches gasoline, especially ethanol-gasoline blended fuel. For example, the OMS-fuel pump in the 1993 is probably ready for replacement. They cost about $400. How do I know this? I owned a 1992 OMC-Evinrude engine. I sold it when it was about 18-years-old, and told the buyer he should plan on replacing the OMS-fuel pump in a year or two. Two years later the fuel pump needed replacement. You might have some rubber hoses that could need attention, too. By getting the newer engine you will have ten years more before the rubber components in the fuel system start to reach end of life with ethanol-gasoline fuel;

--the 2003, if it is a looper--I don't know for certain--should give better fuel economy; it won't be a huge improvement, but it should be better;

--the 2003 with the OIS-2000 optical ignition system should be more reliable than a 1993. Again, coming from my experience with my 1992 OMC engine, you can expect the 1993 engine may need a replacement for the Power Pack. I chased an intermittent in my 1992 engine for months before I isolated it to the Power Pack. That was another $300 part. Replacement of the Power Pack on a more-than-20-year-old OMC engine is probably fairly common.

It is hard to assess two engines I have never seen, so I am assuming that they are both in great condition. I don't know what prices are like these days for these older two-cycle carburetor engines, and I am surprised that a 90-HP used engine would be $3,000. I hope it is in like-new condition for that price.

medic one
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Re: Older vs Newer Johnson 90hp

Postby medic one » Thu Feb 25, 2016 5:37 pm

Thanks jimh,

I had many of those thoughts as well. The only reason I'm even contemplating the '93 is because it looks VERY clean and had a recent rebuild. I haven't had a chance to get hands on like I have with the '03 (which is also very clean with professional maintenance).

I'm in the Puget Sound market. It just seems to be that everything "boat" is more expensive up here. I can understand the vessel value a bit, as we have less UV-effect due to our northerly-ness. But you'd expect some of these motors to be LESS considering the salt water exposure.

Anyway. Thanks for the input.

Peter
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Re: Older vs Newer Johnson 90hp

Postby Peter » Fri Feb 26, 2016 8:11 am

The 2003 is a 60-degree "looper" and the 1993 is a 90 degree cross-flow. The 1993 is simpler. One thing that I like about the cross-flow version is that It can be pull started with a rope. I believe that is not possible with the 2003.

Having said that, the 2003 is a nice motor. I had a 2003 60-degree 150 V6 on my 2nd Outrage 18 and previously had the 150 V6-version of the cross-flow on my first Outrage 18. The 60-degree V6 150 was smoother and quieter at cruise than the cross-flow. The induction system on the 60-degree V6 made acceleration faster than in the case of the cross flow. I would expect to see the same difference on the V4 versions of each.

conch
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Re: Older vs Newer Johnson 90hp

Postby conch » Fri Feb 26, 2016 9:36 am

Different wiring harness between the two engines also. Does either come with controls and wiring?
Chuck

jimh
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Re: Older vs Newer Johnson 90hp

Postby jimh » Fri Feb 26, 2016 10:39 am

conch wrote:Different wiring harness between the two engines also.


That is a very good point. OMC changed to the MWS (modular wiring system) in c.1996. BRP is still using the MWS wiring harnesses.

The two wiring harnesses are easy to distinguish. The older system uses a large, round, red, rubber connector at the engine. The newer MWS harness has multiple rectangular plastic connectors.

phillnjack
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Re: Older vs Newer Johnson 90hp

Postby phillnjack » Fri Feb 26, 2016 7:24 pm

If the 1993 70-HP engine was rebuilt with new pistons, rings, bearings, seals, and so on, then this [engine's powerhead] is to be treated as just a few years old.

The 70-HP will give performance around the same as the E-TEC 90; an older E-TC 90 is not noted for power in the 90-HP of 2003. Evinrude have now made a powerful E-TEC 90 H.O. that is really a detuned 115-HP engine.

The older [three-cylinder] 70 was a proven design. If looked after, it will give many years of service.

The E-TEC 90 will cost a lot more to keep it well maintained over a five year period.

If using the boat in saltwater, you will pay out a lot for gear box seals and a lot more corrosion protection on the E-TEC needs to be kept up.

The advantage of the newer engine is the amount of oil it does not use--that's it.

The fuel consumption is nothing to brag about unless you do a lot of trolling. At maximum speed the two engines will give around the same performance and fuel consumption will be higher on the E-TEC 90 compared to the 70-HP.

If your 70-HP is the Bridgeport version, you could [improve] the performance of that engine and be way ahead of the E-TEC for power. A simple [cylinder] head skim to raise compression and a set of better reeds will go a long way.

An E-TEC that is ten years old might sound good to some, but [the cost of something] would probably be nearing a complete rebuild of the powerhead. And that will be very expensive to have done.

Nobody sells a good used E-TEC.

That is my view of both engines. Personally I would stick with what you know to be reliable at the moment.

Peter
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Re: Older vs Newer Johnson 90hp

Postby Peter » Fri Feb 26, 2016 9:18 pm

The displacement of the 1993 Evinrude orJohnson 70 was 56-cubic-inches. The three-cylinder E-TEC 90 displacement is 79 cubic inches (41 percent greater). The Evinrude or Johnson 70 most certainly WILL NOT provide the same performance as an E-TEC 90, nor will it provide the same fuel efficiency. But in any case he's not looking at an E-TEC 90 but rather two carbureted V4 Johnson 90s.

jimh
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Re: Older vs Newer Johnson 90hp

Postby jimh » Fri Feb 26, 2016 10:30 pm

The old three-cylinder 70-HP from OMC was a classic outboard design, but there is no one who would rather have a 22-year-old rebuilt engine than have a newer E-TEC 90, and I am afraid in a tug of war the 70 would lose.

I believe the original OMC 70-HP displaced 849-CC or 51.8-cubic-inch.

The E-TEC 90 displaces 1295-CC or 79-cubic-inch.

What this sidebar about a 70-HP and an E-TEC has to do with the topic of this thread is beyond my comprehension. I disagree with just about all the conclusions presented above regarding the E-TEC.

medic one
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Re: Older vs Newer Johnson 90hp

Postby medic one » Tue Mar 15, 2016 1:15 am

Thanks for all the input. I ended up purchasing a 2001 Johnson 90-HP Ocean Pro that runs nicely, has good compression, is VERY clean, was used almost entirely fresh water, and received regular maintenance. I just wish the boat I bought it for was ready for the water!

RogueII
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Re: Johnson 90-HP Older v. Newer

Postby RogueII » Tue Jun 21, 2016 12:43 pm

Circling back on this thread in case anyone comes across it in the future. I have run both a 90 Crossflow and a 90 60 degree looper on a 17 Montauk. The looper performs better -- a bit quieter, a bit more torque, smoother idle and a bit more fuel efficient.

Masbama
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Re: Johnson 90-HP Older v. Newer

Postby Masbama » Tue Jun 21, 2016 10:13 pm

I had a 2002 BRP 90 pm my 1977 Montauk. It was smooth, powerful and relatively quiet. Not a gas hog
either.