MONTAUK Maximum Engine Weight

Optimizing the performance of Boston Whaler boats
mb159
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MONTAUK Maximum Engine Weight

Postby mb159 » Fri Jan 15, 2016 8:41 pm

Is a Yamaha F90 four-stroke-cycle engine that weighs 341-lbs too heavy for a 1987 Montauk 17? I see some old threads that say the maximum weight for the transom is 419-lbs. And another thread that show data less than that. I have an opportunity to get this boat at a really good price, but I want to be certain I am okay on weight. I previously owned another 1987 Montauk that had a Johnson 88-SPL two-stroke-cycle outboard that weighed a little over 300-lbs. I appreciate any assistance and advice

jimh
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Re: MONTAUK Maximum Engine Weight

Postby jimh » Sat Jan 16, 2016 12:00 am

The most honest answer is there is no published maximum transom weight specification for a 1987 Boston Whaler MONTAUK 17. There are several good prior discussions. You never cited any of the ones you refer to. I recommend the thread titled Maximum Engine Weight.

In my opinion, a classic MONTAUK 17 can tolerate an outboard that weighs 341-lbs. I base this on my first-hand experience with MONTAUK boats with an E-TEC 90-HP that weighs 320-lbs or more.

Also, in my opinion, a good way to judge the transom weight is by noting the location of the engine splash well drains relative to the static waterline of the boat at rest. If the transom weight is excessive, the engine splash well drains will be submerged below the static water line.

Since you contemplate a four-stroke-cycle engine, there won't be an external oil reservoir; this should eliminate some weight in the stern. You can also consider relocating the battery to be under the center console to shift weight out of the stern if needed to restore proper trim.

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Phil T
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Re: MONTAUK Maximum Engine Weight

Postby Phil T » Sun Jan 17, 2016 8:14 am

I recall prior discussions reviewing engine weight for a classic Montauk and the consensus was the Honda 90 was the limit. I recall it weighed about 355-lbs. My friend Legobusier had this exact setup and the boat did squat a bit in the stern.

One method to evaluate engine weight prior to purchase to see how it affects trim is to add weight the the stern and assess. You can add bags of sand, buckets of water (1 gal = 8 lbs)
Member since 2003
1992 Outrage 17, 1992 Evinrude 115

mb159
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Joined: Mon Oct 19, 2015 10:09 am

Re: MONTAUK Maximum Engine Weight

Postby mb159 » Tue Jan 19, 2016 10:24 am

I greatly appreciate the responses to my query. Unfortunately, what was listed as a "beautiful Boston Whaler", turned out to be anything but. The 2015 Yamaha f90 and the 2015 aluminum trailer were the highlight. The 1988 Montauk itself was an entirely different story. The floor had severe cracking and crazing, and the seller made a decision to "top coat" the interior and deck. He used Awl Grip, and it appears that he used a block fill brush to apply it. The motor, while very nice, did not look good on the transom of a Montauk, and I am sure that it is borderline too heavy. Boat, motor, and trailer were listed for $ 13,500. i was extremely disappointed as I thought I was going be back in a Whaler. Still looking!!!

Mike

jimh
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Re: Used Boston Whaler Boat Sales

Postby jimh » Wed Jan 20, 2016 10:31 pm

Classic Boston Whaler boats that are actually in "beautiful" condition, are re-powered with a modern outboard engine of suitable horsepower, size, and weight, are on a road-worthy, registered, well-fitted trailer in equally "beautiful" condition, and have a realistic asking price from a reputable seller usually sell in about five minutes after the first person that is a real buyer, not a tire-kicker, comes to see them in person.