170 MONTAUK Re-power with Yahama F90

Optimizing the performance of Boston Whaler boats
Montauk2003
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Joined: Wed Apr 20, 2016 12:41 pm
Location: Lake Wylie, SC

170 MONTAUK Re-power with Yahama F90

Postby Montauk2003 » Tue May 15, 2018 12:17 pm

Hi fellow members. I just upgraded the engine on a 2003 170 MONTAUK to a new Yamaha F90. I am not sure what size propeller to install.

I plan to use a stainless steel propeller with a pitch that is good for all-round use, including pulling a small float or tubing. Any input would be greatly appreciated.

Thanks for your help—Danny

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Phil T
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Location: Was Maine, now Kentucky
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Re: Prop - 2018 Yahama 90HP 4-stroke Montauk

Postby Phil T » Tue May 15, 2018 3:54 pm

Danny -

The standing recommendation is a 13-1/4" x 16" Yamaha Performance Series propeller, part # MAR-GYT3B-V4-16.

Engine should be mounted 2 holes up. See FAQ http://continuouswave.com/forum/viewtopic.php?f=7&t=739
Member since 2003
1992 Outrage 17, 1992 Evinrude 115

Montauk2003
Posts: 23
Joined: Wed Apr 20, 2016 12:41 pm
Location: Lake Wylie, SC

Re: Prop - 2018 Yahama 90HP 4-stroke Montauk

Postby Montauk2003 » Tue May 15, 2018 4:50 pm

Thanks Phil for your recommendation.
Danny

Montauk2003
Posts: 23
Joined: Wed Apr 20, 2016 12:41 pm
Location: Lake Wylie, SC

Re: Prop - 2018 Yahama 90HP 4-stroke Montauk

Postby Montauk2003 » Tue May 15, 2018 5:07 pm

Just for your information, the original motor was a Mercury 90 FOURSTROKE which came with a Mercury 13x18 Vengeance propeller. This propeller had a lot of low end torque but I thought engine speed or RPM on the top end were more than I felt comfortable with in the over-40 MPH boat speed range. I just purchased a Mercury propeller adapter kit. The Vengeance propeller will work on my Yamaha. I will see how the Vengeance propeller works and let the team know.

Thank you,

Danny
Lake Wylie, SC

pcrussell50
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Re: 170 MONTAUK Re-power with Yahama F90

Postby pcrussell50 » Fri May 18, 2018 7:51 pm

What happened to your Mercury 90 FourStroke? It's a Yamaha, too. Essentially a Yamaha F100.

I have one on my 1998 classic 17. It's heavy, but otherwise very nice. On a utility boat like a Whaler, I don't mind the bulk. I have other boats with lighter more powerful motors for speed.

-Peter

Montauk2003
Posts: 23
Joined: Wed Apr 20, 2016 12:41 pm
Location: Lake Wylie, SC

Re: 170 MONTAUK Re-power with Yahama F90

Postby Montauk2003 » Fri May 18, 2018 9:15 pm

Hey Peter: I sold my 2003 Mercury 90 FOURSTROKE and upgraded to a 2018 Yamaha F90. The Mercury ran rich, was tough on spark plugs, and the four carburetors needed to be synchronized occassionally. I was going to try a hotter plug but decided not to. —Dan