NAUSET 16 Yamaha 90-HP

Optimizing the performance of Boston Whaler boats
Blackduck
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Joined: Sat Mar 26, 2016 5:04 pm

NAUSET 16 Yamaha 90-HP

Postby Blackduck » Tue Sep 05, 2023 3:41 pm

[An earlier discussion about this boat focused on engine mounting height and possible changes and benefits.]

I did not change the engine mounting height for the Yamaha 90-HP two-stroke-power-cycle engine on my NAUSET 16 boat [as was discussed in the prior thread], and I left the engine as it had been mounted [in the lowest possible position and] using the blind mounting bolts.

With a Yamaha aluminum propeller [of unknown number of blades and] 17-pitch, the NAUSET 16 boat is very responsive. The Yamaha 90-HP engine accelerates at full throttle to 5,500-RPM, producing a boat speed of 42-MPH speed over ground by GPS.

I feel that less than 1-MPH speed would be gained if the engine were raised two-holes higher.

I feel that replacing the current aluminum propeller with a better propeller might add a bit more boat speed--but not very much.

Advice I got from Jim and Phil [who both recommended against buying and installing a jack plate] was good advice, and I saved a lot of time and money [by not buying and installing a jack plate].

The 50-year-old NAUSET 16 is shown in Figures 1, 2, and 3.

nauset1.jpg
Fig. 1. A NAUSET 16 with all,original wooden components, now reparied.
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nauset2.jpg
Fig. 2 The dock were the photographs were taken.
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nauset3.jpg
Fig. 3. A 50-year-old NAUSET 16.
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The original wooden components were taken apart, stripped, repaired, and put back together. To replace the original wood with new wooden parts would have been a lot less work, but the plywood available today is just not suited or intended for marine use.

jimh
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Re: NAUSET 16 Yamaha 90-HP

Postby jimh » Tue Sep 05, 2023 11:41 pm

Getting a boat speed of 42-MPH sounds quite good to me for an old 16-footer and an aluminum propeller.

The boat looks very nice, too. Where is that dock?

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Phil T
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Re: NAUSET 16 Yamaha 90-HP

Postby Phil T » Wed Sep 06, 2023 8:16 am

After reading your post and a good night sleep, I think you should upgrade the propeller to the Yamaha painted stainless steel model in 13 x 17.

It will not need to be replaced if you hit a buoy or debris.

The boat will perform better at all speeds.

Just be happy you don't need an Enertia propeller for $860--No foolin'.
1992 Outrage 17
2019 E-TEC 90
2018 LoadRite 18280096VT
Member since 2003

jimh
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Re: NAUSET 16 Yamaha 90-HP

Postby jimh » Wed Sep 06, 2023 8:35 am

Again, Phil and I agree: an aluminum propeller has about zero tolerance for a blade striking anything, while a steel propeller will tolerate a blade strike with some sort of softer material without any deformation of the steel.

If you do any boating in shallow water, there will be some sort of encounter between a propeller blade and something in the water at some point in your future.

Blackduck
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Re: NAUSET 16 Yamaha 90-HP

Postby Blackduck » Wed Sep 06, 2023 10:37 am

dockViewFromHouse.jpg
Fig. 4. The dock seen from shore.
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Dock is located on Winnapaug Pond in Westerly, Rhode Island. The pond is saltwater and tidal. The location is the west end, north shore. I built the dock 15 years ago. It is 100-feet long, as was needed to get some water depth. The photo from my front yard.