MONTAUK 17 Yamaha F70

Optimizing the performance of Boston Whaler boats
Posts: 10
Joined: Wed Jun 29, 2022 5:04 pm

MONTAUK 17 Yamaha F70

Postby Boatshop6581 » Mon Jun 19, 2023 12:46 pm

I have been very pleased with the performance my MONTAUK 17 with a YAMAHA F70 engine, the lightest intermediate-size engine on the market, only weighing 253-lbs.

With the factory-installed propeller [of unspecified material, number of blades, diameter, pitch, and model designation] and one person aboard, the top boat speed is 38-MPH; with two people aboard, 20-gallons of fuel, and assorted supplies, the engine accelerates the boat onto plane very easily, and maximum boat speed is around 35-MPH.

After the engine has finished the break-in period or in a year or in two years, I may explore a stainless performance propeller.

All 90-HP engines on the market weigh at least 100-lbs more [than the Yamaha F70 does at 253-lbs, making those engines weigh at least 353-lbs]. [An engine weight of 353-lbs] is heavy for the [MONTAUK 17].

User avatar
Phil T
Posts: 2624
Joined: Thu Oct 22, 2015 6:08 pm
Location: Was Maine. Temporarily Kentucky

Re: MONTAUK 17 Yamaha F70

Postby Phil T » Mon Jun 19, 2023 12:51 pm

There is no factory propeller

The selling dealer sold a propeller that they or the buyer selected.

Many owners have repowered their Montauk with an F70. (Wide open throttle is 6300). Their testing resulted in these recommendations:*

13 x 17 Yamaha Painted SS
13.25 x 14 Yamaha Performance Series
13-1/4” x 17” Turbo 1
13.25 x 14 PowerTech SCP

* Engine should be mounted "two holes up". Meaning the top engine bolt goes through the 3rd hole down from the top of the bracket and into the transom. The bottom bolts should be in the middle of the lower slots.
1992 Outrage 17
2019 E-TEC 90
2018 LoadRite 18280096VT
Member since 2003