86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

[acarter92]

So, I have a 17' fish and ski style boat (Spectrum Blue Finn) that I completely rebuilt from the bilge up last winter. It's pretty much a new boat, except for the hull and motor....

This past summer I used the boat for a little bit of everything. We even took it up to Maine and spent a week on a lake and some time on the coast with it. The boat gets used a whole lot, and it's not going anywhere.

Now, the outboard on it is an 86' 70hp evinrude that runs pretty good. Overall it's a good motor, but it's getting old and needs attention fairly often. It's never let me sit, but that's because I'm always ahead of the problems, but I'm sure it's only a matter of time...

I've been thinking about getting a new/ newer 4 stroke to replace it this winter. A 40 or 50 horsepower, the 70 is nice but I really don't need all that power, I never cruise at full throttle and don't need near as much power to pull tubers/ skiers (it's a light boat). Some of the things that attract me are reliability, less noise, and less fuel consumption which is a big one. I burn about 4 or 5 gph at a 20mph cruise speed, I wonder how much better I could get? I have my eye on the 40 hp honda, but I'm open to options.

So what do you guys think? Would it be worth it? Would you do it? I know there is no right answer, just looking for opinions/ experience, and maybe somebody to talk me out of it...

Thanks is advance,
Austin

 

[Bob_VT]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

That's a steep investment ....... how long will it take to re-coup the money....... actually never. Just not worth it in my opinion..... would be even cheaper to completely rebuild the 70.

 

[Frank Acampora]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

Recently I was water testing a 30 HP four cycle Suzuki. On a 14 foot flat bottom closed bow runabout, It topped out at 32 MPH so the power was good. It ran quietly enough that we could talk over the noise at full throttle so that's a plus too. However, We did use about 1/2 gallon (from a one gallon tank) to cover about 2-3 miles at full throttle so I don't think the fuel economy is that much better than a 2 cycle outboard.

It did smell less and did not smoke and that is a positive.

New 4 cycle engines are expensive so from a monetary view that is a negative. They are worth more at resale but that is not really a factor in your case.

Ultimately it is your money and your choice--some people like a new car every two years, just because. You need to weigh the expense versus the perceived benefits and decide if it is worth it to you.

Would I do it? It depends. That little Suzy did impress me, but my personal engines are older cheap Chrysler and Force. It takes a lot of gas to offset the cheap initial price I pay for them. But, I don't have a monthly note to pay and gas purchases are spread out over a long time

 

[JB]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

You say your 70 needs attention once in a while but otherwise runs good. What sort of attention does it call for?

That is a great engine. 26 years is not really old for an outboard, especially a JohnnyRude looper. It was 20 years ahead of the industry back then, so is not obsolete.

I think I would detail the 70 and stay with her.

On the other hand, if you simply have new motor fever (been there, did that) a 4 stroke 50 would be nice. Quiet, no smoke or fragrance (some call that stink) a bit more economy and a lot more money. Routine maintenance would be more complex and expensive, too.

 

[Silvertip]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

You might find that the 40% reduction in power plus the performance difference between two and 4-strokes may drop your expectations more than you think. Here are some facts: It doesn't matter whether you have a two or four stroke motor. Both will use very close to the same fuel at wide open throttle. In fact in some instances, a two stroke actually burns less. The Yamaha web site is a very good source for fuel consumption comparisons. Check their performance bulletins. If you are pulling tubes, keep the 70 or upgrade to a 70 4-stroke. It will probably not have the hole-shot the two stroke has but you will not suffer the performance losses by dropping to a 40-50 4-stroke. Also be aware that when you compare fuel economy -- you must check fuel consumption at the same boat speed, not the same engine rpm. A two stroke will almost always be pushing the boat faster than a 4-stroke at any given rpm. This is due to the difference in gearing and prop selection to compensate for the differences in the designs.

 

[acarter92]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

Thanks for the responses...

I'll probably end up keeping the 70, but I'm still going to do some research. As far as paying for itself, I don't think it would in 20 years, and I wouldn't be getting it for that reason. Just like I don't expect the boat to pay for itself, because it won't ( I don't catch that many crabs ) I really like how quiet they are. This summer I got pulled over for a safety check at the local lake, the boat police had a 200hp yamaha. They were rafted next to me for a few minutes and if it weren't for the water coming out of the pisser I wouldn't have know it was running ( I really couldn't hear it idling 5 feet away). It would also be very nice not to have to deal with mixing oil all the time. My oil injector was unhooked by the PO because he was worried about it failing (which I may hook back up in the future).

All the things I've done to the 70 this year were minor. The tilt motor went bad, starter, rectifier... and a few other minor thing's I'm forgetting about. It also leaks oil between the carbs and cylinders, but that can be fixed. It was quite inconvenient this summer when the rectifier went in Maine and I had to keep hauling the battery up to the house to charge it every day or so... The starter went while on the water and I had to get towed back (no big deal, but it could have been worse).


I'll probably give the 70 a good cleaning up, replace some gaskets, get the carbs rebuilt and call it good, but keep the comments coming...

Thanks,
Austin

 

[rico suave]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

Whenever my friends and I get into this discussion they caution me about replacing my old motor that runs well. I have a 1971 Johnson 85 hp, and most of my friends have newer 4 stroke models. They love their 4 stroke, for the obvious reasons, but hate trying to troubleshoot problems on them. The cost of parts is an issue too. Even on my 1971 Johnson I can buy many of the parts on Ebay as used, NOS, or new, and the costs are mostly reasonable, and I've never had to rely on a dealer for repair. Just something to consider.

 

[rico suave]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

Can I take that last post back? I didn't knock on wood. ....I fear God will strike my engine dead in June when I go back to start it up. Damn!

 

[phillnjack2]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

There is always plenty of parts for a tried and trusted product.
I have come across a lot of what i consider new engines that are 4 stroke that seem to be very worn out !!!
the 2 strokes are easier to work on,cheaper on parts ,and give a decent lifespan.

To have more power on tap than you need is a good thing.
Re-build your 70hp and save a fortune and enjoy the reliable tried and trusted engine ...


phill

 

[acarter92]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

Whenever my friends and I get into this discussion they caution me about replacing my old motor that runs well. I have a 1971 Johnson 85 hp, and most of my friends have newer 4 stroke models. They love their 4 stroke, for the obvious reasons, but hate trying to troubleshoot problems on them. The cost of parts is an issue too. Even on my 1971 Johnson I can buy many of the parts on Ebay as used, NOS, or new, and the costs are mostly reasonable, and I've never had to rely on a dealer for repair. Just something to consider.

That is a good point that I didn't think of....

There really isn't anything that I can't do (or can't learn to do) on my motor, with the exception of rebuilding the lower unit. I imagine a new 4 stroke would be just like a new car or truck, too many electronics....

Austin

 

[Fleetwin]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

I replaced a 70 Johnson "looper" with a 60 Merc. 4-Stroke.

I loved the old Johnson, it was a real powerhouse on my hull.

The 60 runs just as fast but the power band is completely different. It just pulls smoothly throughout the throttle range. Better at slower speeds.

The fuel economy is astounding compared to the old 70. About 1/3 to 1/2 plus you can't hear it run.

Yes, it was a big investment but my boat isn't going anywhere either.

 

[rico suave]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

The fuel economy is definitely an issue. Even on it's best day the 4 stroke will beat out the 2 stroke, but if property tuned and set one can minimize the fuel consumption on their 2 stroke.

 

[Silvertip]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

The fuel economy is definitely an issue. Even on it's best day the 4 stroke will beat out the 2 stroke, but if property tuned and set one can minimize the fuel consumption on their 2 stroke.

You didn't see my post about checking Yamaha's web site for fuel economy numbers did you? Yes -- at any given engine RPM a four stroke burns less fuel than a two stroke. That should be obvious since a four stroke only fires once every other revolution. However, a two stroke at the same RPM is pushing the same boat faster. Therefore one needs to compare economy numbers carefully. I've seen Yamaha tests where the two stroke is more economical than the same size four stroke. At wide open throttle both engines are very close. As for noise, again at wide open throttle dB ratings are quite close. Most folks mistake the four stroke sound as quieter when in reality it is just a "different" noise.

 

[rico suave]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

I did see the post but I have to admit that I'm skeptical, at least about the fuel economy aspect. Since the fuel disbursement is measured electronically on the 4 stroke (that's my understanding) then that alone should save fuel over carburetors and the vacuum suction and mechanical approach. It does make sense though that when I hit my sweet spot on the throttle that the two types would be closer on the fuel consumption. I think when all things are considered, especially stopping, starting, and operating at lower RPMs that the 4 stroke has clear advantages. The problem is that those of us with 2 strokes can't always operate at our optimum benefit whereas it just happens with the 4 stroke. Still, I wouldn't trade my old 2 stroke for a newer 4 stroke since even if I do save money on fuel I'm going to get my *** kicked in a major way on the price.

 

[steelespike]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

If your thinking new motor you should check out the Evinrude Etec.(2 stroke direct injection)
They have a 50 and a 60 that weigh about 240 lbs.They meet and exceed all CARB requirements.
They have Very few moving parts require fewer less complicated service intervals,no break in period,
No service for 3 years or 300 hours.
When checking fuel use compare mpg not gph.

 

[nwcove]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

It would also be very nice not to have to deal with mixing oil all the time. My oil injector was unhooked by the PO because he was worried about it failing (which I may hook back up in the future).

the mixing oil deal is an inconvienence....but a small one. i wouldnt even consider re-connecting the oil injection system

 

[jasper60103]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

It would also be very nice not to have to deal with mixing oil all the time. My oil injector was unhooked by the PO because he was worried about it failing (which I may hook back up in the future).

the mixing oil deal is an inconvienence....but a small one. i wouldnt even consider re-connecting the oil injection system

+1
Yea, no big deal for me either. My handy mixing bottle makes it simple.
I currently mix oil for my weedwacker and snowblower, one more motor doesn't make any difference to me.

 

[acarter92]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

Steelspike, good suggestion, I really like that series and the more I think about it I would probably go that route. The smooth running/ idleing of a 4 stroke but all the benefits of a 2 stroke. Pretty light too, and not bad on gas...


I think I've talked myself out of getting a new motor (with your help), but nothing is for sure... If I do keep the 70 I think I'll bring it in the shop this winter and make it run like new again. I think a GPH meter is on the list too, so I can find my optimal cruising speed for the best fuel economy. I'm sure that will pay for itself by the end of the season.

As far as the mixing goes.... It's not a BIG deal by any means, but it is one more thing I have to deal with when getting ready to use the boat. I also think most that have to mix their gas don't burn near as much fuel as me. It's not unusual for me to burn through 5 or 6 tanks (6 gallons) in a weekend. I have a pretty efficient mixing process but it's still a 10 minute project before a weekend...

Austin

 

[steelespike]

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

There are flow meters that can calculate mpg.

 

[Home Cookin']

Re: 86 70hp Evinrude vs New 4 stroke 40 or 50 hp...

I have a mid-80's 70 on a boat that I bought to replace a mid-80's 70 when it encountered a problem that was not economical to fix. It's a great motor. I've been having some problems, though that are hard to diagnose (one intermittant electrical short took 1 1/2 years to find).

If I had money lying around I'd replace it, but only to increase dependability. Few people will recapture the price difference in fuel savings; you might in repair shop savings and the cost of down time*. For some people, the risk of an old motor is also a safety issue.

*You pay a lot for recreation, and if your boat doesn't work, you are losing money, unless you have an extra boat. Something to consider.