1987 15 Sport CC F70: Amazing Results

Optimizing the performance of Boston Whaler boats
Simon
Posts: 35
Joined: Wed Nov 18, 2015 9:44 pm

1987 15 Sport CC F70: Amazing Results

Postby Simon » Sun Feb 07, 2016 1:43 pm

Hi All. I am not sure if [the "amazing results" are due to] the configuration of this [1987 Boston Whaler Center Console 15] boat. I have the fuel tank under the center console and one battery under the bench seat. This boat runs really fast and surprisingly quite stable. I followed the Yamaha break-in process by running the first hour under 2000-RPM, the second hour on plane around 3500-RPM, and then in hour three to three-and-a-half, I took the boat to wide-open throttle a few times.

For those familiar with the bay area, I launched from Martinez and headed out towards Vallejo under the Carquinez Bridge, then back towards the Benicia Bridge and past Mothball Fleet into Pittsburgh. By the time I got to Pittsburgh the engine already had close to three hours of break-in and approximately 30-miles on the water.

I am currently running a Yamaha aluminum 17-pitch propeller. The [15-footer] jumps on plane instantly, and this is with 12 gallons or full-tank (although tank has sticker stating 18 gallons), my gea,r and one buddy that weighs 140-lbs. I'm at 155-lbs. The engine was able to hit 6300-RPM really fast, against the current (six-foot outgoing), and the boat hit 43.1 [assumed to be miles per hour] with very little trim. The first two full-throttle runs were 41.4 then 42.1 [again, assumed to be MPH] without trim. Since I don't have a GPS receiver and a chartplotter yet--still waiting on release of G07 XSE--the device used was a Garmin etrex 20. So maybe the data I have could be just a little off.

With just a little trim, I can feel the boat accelerate much quicker at the higher-RPM range. I backed off the throttle less than three seconds after a little trim since I am still getting used to this boat.

I think with the combination of the weight in front and the F70 this boat will probably hit 45-MPH or faster, especially if I were to run with the current. I was just looking for a propeller and engine combination that gives it a good [acceleration from a standing start at full throttle] and decent speed, and I could not be any happier with the results.


First time I've seen the boat float in person. The waterline with the F70 is below the two drains.
[NOTE: the thumbnail images below are links to much larger images--jimh]

Image

I put a Yeti cooler in the foredeck for little more added weight, but probably didn't need to.

Image

Spent 9 hours on the water with a little bit of sturgeon fishing.
Image

43.1 mph on aluminum 17" prop.
Image


Thanks to all that has helped me in this process. See you guys on the water!

Simon
1987 15' Sport CC

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Phil T
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Re: 1987 15 Sport CC F70: Amazing Results

Postby Phil T » Sun Feb 07, 2016 1:54 pm

Simon--glad to see you are dialed in and enjoying the boat. Well done.
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Whal
Posts: 35
Joined: Thu Jan 14, 2016 7:11 am

Re: 1987 15 Sport CC F70: Amazing Results

Postby Whal » Sun Feb 07, 2016 8:53 pm

Simon, welcome to the F70 club.How do you like that fuel effectentcy?

Simon
Posts: 35
Joined: Wed Nov 18, 2015 9:44 pm

Re: 1987 15 Sport CC F70: Amazing Results

Postby Simon » Mon Feb 08, 2016 3:06 am

Thanks guys.

I'm taking the boat out in the morning so i'll make sure to fill up the tank to see how much was used last time. I will report back when I figure that out.

Simon
1987 15' Sport CC

Huckelberry145
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Re: 1987 15 Sport CC F70: Amazing Results

Postby Huckelberry145 » Mon Feb 08, 2016 8:07 am

I can't believe you got those results out of an almost two year old engine, maybe one built in the month of January but not one built back in 2014.

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Dutchman
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Re: 1987 15 Sport CC F70: Amazing Results

Postby Dutchman » Mon Feb 08, 2016 2:33 pm

Huckelberry145 wrote:I can't believe you got those results out of an almost two year old engine, maybe one built in the month of January but not one built back in 2014.

Why not [believe the results reported]?

[Simon] and his buddy together only weigh a couple of pounds more than me--[they're] really light guys in a light boat with 70-HP. I believe [the boat speed indicated by] the Garmin.
EJO
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50th edition 2008 Montauk 150, w/60HP Mercury Bigfoot

Simon
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Joined: Wed Nov 18, 2015 9:44 pm

Re: 1987 15 Sport CC F70: Amazing Results

Postby Simon » Wed Feb 10, 2016 1:33 am

Whal wrote:Simon, welcome to the F70 club.How do you like that fuel effectentcy?


Whal - I was able to get 8.88 mpg on that first trip. Not bad at all.

Simon
1987 15' Sport CC

BlueSmoke
Posts: 25
Joined: Wed Dec 09, 2015 10:06 pm

Re: 1987 15 Sport CC F70: Amazing Results

Postby BlueSmoke » Wed Feb 10, 2016 9:42 am

sweet ride! speed sounds right where it should be!

Is that a full montauk consule?

first pic it looks your engine has an earring on the starboard side? or is that a sticker?

Simon
Posts: 35
Joined: Wed Nov 18, 2015 9:44 pm

Re: 1987 15 Sport CC F70: Amazing Results

Postby Simon » Wed Feb 10, 2016 11:18 am

BlueSmoke wrote:sweet ride! speed sounds right where it should be!

Is that a full montauk consule?

first pic it looks your engine has an earring on the starboard side? or is that a sticker?


Thanks blue smoke. It is a sweet little ride.

I bought the boat with the railings on already. The front looks a little different from the montauk so not sure where it came from.

The earring is a tag left on by the shop. It's the factory tag reminder to add engine oil. I just took it off.

Simon
1987 15' Sport CC

Simon
Posts: 35
Joined: Wed Nov 18, 2015 9:44 pm

Re: 1987 15 Sport CC F70: Amazing Results

Postby Simon » Wed Feb 10, 2016 11:22 am

Whal wrote:Simon, welcome to the F70 club.How do you like that fuel effectentcy?


Hi Whal, I'm assuming you also run an F70. Do you use a transom saver? Or something that props the motor up while under tow? I currently just use those tabs that presses against the motor mount when engine is lowered. I wonder if that is enough support.

Simon
1987 15' Sport CC