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Have a 1967 sakonnet that i need to repower. Had a 2000 honda 50 that weighed 200 lbs. I want more speed and need to know if a new four stroke yamaha 90 that weighs 350 is going to be too heavy


(EDIT: please follow guidelines at the top of this page and us the FULL 4 digit year)

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A bit heavy, but I ran a suzuki DF 70 on my Montauk, with an 8 HP honda kicker for a weight that exceeds 350# with no ill effect. I did move my dual batteries onto the floor under the center console.

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Thanks. I was thinking about a much lighter etec but the bad reviews scared me off

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Bad reviews ? 2009 , 90hp 700 hours no issues. I would be curious to see see who posted those. Just my my opinion.

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While there is no transom weight rating for the 16'7 hull, you can go all the way up to 400 lbs. You may want to shift some weight forward to help static trim.

As for those bad reviews, highly suspect a few sore apples. Not on any whaler forums.

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The question is asked many times here on this website:

"Can I install a modern heavy outboard onto my Boston Whaler 16 boat (Sakonnet, Nauset, Eastport models) that is more than 50 years old?"

the standard response is: "The hull is rated to 100 hp."

Before making such a decision to repower, I suggest the appropriate response should be: "What is the overall condition of your boat?"

Do you have cracking/crazing and weld-line (AKA green-line) separation?

Does your boat have damage/repairs?

Have you weighed your hull to determine the extend of possible water infiltration into the foam core?

Have you done a hammer tap of the hull to see if there are any areas of the hull where the foam core has separated from the fiberglass hull?

Note: Moisture meters are generally not reliable on Boston Whaler boats because they most often spike, even on newer than 2002 post classic, Edgewater, FL manufactured boats.

The reason why I am raising this issue is because here in New England, we are seeing instances of catastrophic failures of 16 hulls of the 1960's vintage after they were repowered with modern, heavy outboard motors.

Every man-made plastic product has a lifespan. Some boats last longer than others, with proper maintenance and care by the owner.

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I have a 1977 sport hull with a 2001 100hp Yamaha. I think the engine weighs about 380 pounds. The boat had an engine bracket added to support the motor (before I bought it). The balance in the boat is fine with the heavy motor and it goes very fast. My transom appears to be in solid shape, but I don’t think I’d have a motor that big on the 40 year old hull without the added bracket.

I appreciate the extra speed, but I could certainly live without it. I see a lot of older whaler hulls with 90hp Yamaha’s on them. Many folks have told me the transoms can support larger motor weights/hp than the capacity ratings, but I don’t think I’d push past them especially with an older hull.

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Weatherly makes some good points. My 1978 Montauk 17, purchased originally by my father, always cleaned and waxed after each use, stored inside its whole life, but it still has some isolated spider cracking in the floor(nothing more than an inch). Its 40 years old. I spent countless hours assessing the hull, and making some minor repairs. But, I didnt know the structural integrity of the transom until the original motor was removed AND holes were drilled for my repower. Fortunately, the wood chips came out looking like new and had good density. Same for the fiberglass. When you are dealing with old boats, get ready for any and everything.

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Re Etec- my 2006 225 ran Flawlessly for the first 1100 hours, always running XD100 oil, never once had to do anything other than 300 hour services and routine maintenance.
Then one day running at 4000 rpm it grenaded when a piston wrist pin lost lubrication.
Personally, I wouldn't buy another 2-stroke after that experience. There's just something about machinery running in a bath of oil that is more appealing to me.

Most people take between 10 and 20 years to get to 1000 hours, so problems don't show up for a long time, if ever.

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Here is an example of catastrophic hull failure on a 16 smirkless boat. The owner of this boat informed me that the failure happened while underway so the heavy, high horsepower outboard was definitely a contributing factor to the hull damage.

Look at the damage to the portside rear quarter area shown in image number #3. The fiberglass was ripped away by shear stress while underway.

[url]
https://sfbay.craigslist.org/eby/bpo/d/17-whaler-montauk/6657833274.html[/url]

Repower an old 16 that has water infiltration and foam core separation and damage like this can result. This is the 4th example of hull catastrophic failure I have seen in the last 5 years.