1973 Montauk Re-power for a Fisherman

Optimizing the performance of Boston Whaler boats
Duckmanreno
Posts: 22
Joined: Mon May 09, 2016 3:58 pm

1973 Montauk Re-power for a Fisherman

Postby Duckmanreno » Mon Jun 10, 2019 6:46 pm

I have been toying with re-powering my 1973 Montauk 17 for a long time, and I am finally getting some encouragement from my wife.

I am looking at the Yamaha F70, Tohatsu TLDI 90, and E-TEC 75 and 90. I have read many of the threads about re-powering over the years but I have a couple of twists.

First I troll a lot so which of these choices might be better for a slow troll?

I am trying to get away from needing to use a kicker all the time.

Second, I normally fish between 5000 to 6000 ft elevation. Traditionally you battle that on older two-strokes with prop selection and jet changes. I'm going to assume modern outboards will overcome this but I'm not sure.

I appreciate any input.
Thanks Joe
1974 Montuak
2021 Yamaha F70

Chris70
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Joined: Sat Feb 09, 2019 8:48 pm
Location: Long Island

Re: 1973 Montauk Repower. Fisherman

Postby Chris70 » Mon Jun 10, 2019 9:41 pm

I re-powered my 1970 last year with a 2017 Mercury 90 FOURSTROKE. My boat is only used for fishing. The motor so far has been great to me. I put 215 hours on it the first season. I don’t know what species you fish ,lure types you use or desired trolling speeds. I can tell you with mine I can troll from speeds from 3.5mph-5mph with out any problems. My boat is rigged with conventional cable controls. I use a 13.75x15 Stainless propeller.

Most outboard manufacturers offer optional digital controls and digital gauges that have “troll control” . This allows you to jog engine speed up or down with a button to control troll speed. I know for sure it’s available with Mercury and Suzuki. I’m not sure about the Evinrude or Yamaha.

jimh
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Location: Michigan, Lower Peninsula
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Re: 1973 Montauk Re-power

Postby jimh » Tue Jun 11, 2019 8:01 am

For a classic 17-foot MONTAUK boat, my impression is the most popular engine for re-powering has been the Evinrude E-TEC 90-HP legacy three-cylinder engine. The Evinrude E-TEC 90-HP engine is a very good fit for the MONTAUK in terms of its size, weight, appearance, and performance.

The Evinrude E-TEC 90-HP engine, like all E-TEC engines, will run very well at low engines speeds and will deliver extraordinary fuel economy. Even with my 225-HP E-TEC pushing my 24-foot boat, the fuel economy is greater than 10-MPG at trolling speeds. It takes about five hours to consume one gallon of fuel.

The E-TEC engine running on a modern lubricating oil like Evinrude XD100 does not produce any smoke in the exhaust.

WIth an E-TEC you will be freed from making oil changes of the lubrication oil and oil filter, which are, at the least, an annual chore usually done before winterizing the engine. Also with an E-TEC the engine performs its own winterizing procedure, and this also frees you from having to run fogging oil into the engine.

Evinrude generally offers a three-year or five-year warranty on their engines, and on occasion has promotional periods with ten-year warranty coverage.

I have owned an E-TEC since 2009, and its has been a very reliable and very strong engine. I am not acquainted with the features available on the 90-HP model regarding electronic control of engine speed in small increments, but I have such a function on my 225-HP engine through its electronic shift and throttle (EST) controls.

Regarding use at high elevation, the E-TEC engine has a barometric sensor which should compensate for operation at high altitudes. I would not expect there to be a fall-off in performance due to operation at 5,000-feet.

Since this is probably the most important concern, i recommend you check with the manufacturer on any engine you are considering purchasing, and ask them specifically about operation at 5,000 to 6,000-feet elevation. You shouldn't buy an engine without the complete assurance from the manufacturer that it will be able to operate normally at those altitudes.

Duckmanreno
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Joined: Mon May 09, 2016 3:58 pm

Re: 1973 Montauk Re-power for a Fisherman

Postby Duckmanreno » Tue Jun 11, 2019 1:39 pm

I appreciate the excellent responses.
I generally troll for trout with lures at a slow 1.8-2.2 mph. Surprisingly my ancient 80 hp 3 cylinder merc trolls well at 2.3 mph when trimmed right. I have not yet determined if Etec has a slow rpm adjustment that has been mentioned but Yamaha does. I have been leanto an ETEC.
I am also hampered a bit by the fact that there are not too many dealers near me. Hard to get price comparisons. I don't mind traveling dome but might be a mistake to buy an engine too far away.
1974 Montuak
2021 Yamaha F70

jimh
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Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
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Re: 1973 Montauk Re-power for a Fisherman

Postby jimh » Tue Jun 11, 2019 1:46 pm

My theory on what engine to buy: buy the engine that fits your needs and has the best local dealer support. A huge factor in my decision to buy the engine I did was my very good impression of the dealer that would sell it and then service it. It also helped that initially I could re-use all the engine rigging because I was sticking with the same brand.

Duckmanreno
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Re: 1973 Montauk Re-power for a Fisherman

Postby Duckmanreno » Mon Jul 01, 2019 3:56 pm

Well a bit of an update.

Still checking prices and doing some more research but here goes.

Suzuki is out because no dealer anywhere near me.

The E-TEC—which was my preferred engine—seems to be priced on the high end. I just can't seem to find a good price on one in a reasonable [distance] from me.

I heard a rumor that the TLDI 90 is being discontinued. Seems like a good value for the price but this was a bit of a turn off.

I have found what I consider good prices on the Mercury 90 and Yamaha 70. I like both dealers and their price for installation is similar. The Mercury [90] is priced about $350 more [than the Yamaha 70].

Leaning to the Mercury. I am meeting with dealer to pin down cost for controls, wire harness, and the rest. Possibly able to use my existing controls which might save money.

I like both engines and both have a slow troll adjustment.

One thing I see is this is probably the wrong time of year to buy. Considering waiting until end of the year to see if any rebates come out.

I appreciate the expertise on the site.

Joe
1974 Montuak
2021 Yamaha F70