Whaler Central - Boston Whaler Boat Information and Photos

Posted by beninga on 05/12/15 - 12:55 PM

I am fixing up/restoring a 1975 17' Montauk. I am going to buy a new 4 stroke motor for it. I have been told that a 90 hp is what I need, but I have also been told that the weight difference between a 90 hp and a 70 hp is so much that I will get about the same top speed out of the 70 hp and a smoother ride without so much weight on the aft. Any comments or ideas. Thank you Whaler World

Posted by action on 05/12/15 - 1:34 PM

FWIW...I have a 1988 Montauk with an ETEC 90 and it is great. It seems to get about 5MPG and uses very little oil. Some of the guys I know have actually changed over from 4 stokes to ETEC's recently. I also heard that the new ETEC's do not require any service for 5 years or 500 hours.

Posted by WRufus on 05/12/15 - 7:08 PM

I have the yamaha f70 and love it on my 1989 Montauk. It is extremely quiet, starts instantly and sips gas - 5 gallons is all you need for running hard most days. The motor is only 257lbs and I also moved the batt to the console. Both result in very well balanced hull and I am very happy with the performance.

Edited by WRufus on 05/12/15 - 7:10 PM

Posted by Joe Kriz on 05/12/15 - 10:54 PM

beninga wrote:
I am fixing up/restoring a 1975 17' Montauk. I am going to buy a new 4 stroke motor for it. I have been told that a 90 hp is what I need, but I have also been told that the weight difference between a 90 hp and a 70 hp is so much that I will get about the same top speed out of the 70 hp and a smoother ride without so much weight on the aft. Any comments or ideas. Thank you Whaler World

If you haven't looked in our Article section and read the "Current Engine Choices and Weights", I suggest you do so.

Posted by sraab928 on 05/13/15 - 3:57 AM

action wrote:
FWIW...I have a 1988 Montauk with an ETEC 90 and it is great. It seems to get about 5MPG and uses very little oil. Some of the guys I know have actually changed over from 4 stokes to ETEC's recently. I also heard that the new ETEC's do not require any service for 5 years or 500 hours.

The new G2's (larger hp) are 5 years 500 hours - the 90 E-Tec remains 3 years or 300 hours for first service.

Posted by HBeric on 06/06/15 - 8:35 AM

Consider a Tohatsu TLDI 90.

This engine weighs about 330 pounds (only slightly epheavier than the E-Tec), has a 5 year warranty, comes with controls and gauges, is about $2,000 cheaper than the E-Tec, and has been performing superbly on the back of my 17' Montauk for the past few months - very happy with this engine so far.

Posted by bradsc on 06/06/15 - 3:24 PM

the smooth ride in a montauk is going to depend on water conditions a great more than motor size. Some days you will get beat to death and others it is OK. They are still a great all around boat! I had a Yamaha 90 2 stroke since 1998 and repowered last year with a Yamaha F70. With 2 on the boat the 70 is perfect. It has plenty of hole shot and cruises above 7mpg. Our range has been the biggest improvement, we go all day long and use between 1/2 and 3/4 of a tank of gas.

So, if you will be carrying a big load and top end is important, a 90hp might be your best choice. If you want range and just cruise around, the 70hp will be the way to go.

Good luck on your restore and repower.

Posted by Phil T on 06/07/15 - 9:20 AM

You were told:

have also been told that the weight difference between a 90 hp and a 70 hp is so much that I will get about the same top speed out of the 70 hp

Absolutely wrong.

The difference between a 90 hp and 70hp for wide open throttle speed generally speaking is ~ 5 mph all things being equal.

The one condition where you need the 90 is having a full load of gear and passengers in nasty seas and are trying to climb up a large swell before it breaks on you. Still nerve racking.

You were told:

smoother ride without so much weight on the aft

Again, so utterly wrong.

I suggest you talk to and listen to someone else, someone who actually knows what they are talking about.

Posted by ursaminor on 06/08/15 - 9:01 AM

#10

I see that you're looking to repower with a 4 stroke and the 4 stroke 90 HP engines do weigh more than what the original 90 HP 2 stoke engines did. That said, there are plenty of these boats with 90 HP 4 strokes on them and there are ways to help compensate for the additional weight on the transom such as moving the battery or batteries into the console. The main drawback of having the heavier engine is a higher minimum planing speed than what it would be with the equivalent lighter engine as well as the boat sitting lower in the water at the transom when at rest.

Many have repowered recently with the newer 70 HP Yamaha 4 stroke and seem pleased with its performance, we chose the 90 HP Etec and are very happy with its performance and fuel economy.

How you use the boat will be the main factor, if you plan on bringing 3 or 4 people out with you frequently the extra HP can be welcome. Because of the "out of the hole" power, ours has become the preferred water skiing tow boat in our area and will pull an adult slalom skier at 30 - 35 MPH easily. I've seen 42-43 MPH on the GPS with a light load and it's still capable of planing at 12-14 MPH, very useful when it's choppy. Good luck, it's hard to go wrong with any of the new engines.