Whaler Central - Boston Whaler Boat Information and Photos

Posted by Doug V on 02/22/08 - 6:49 PM

The owner's manual cautions that the maximum 70 HP installed on the 15 creates a "high performance" craft (not an exact quote, but something close to that).

I repowered a 15 with a 70 HP Yamaha back in the 80's. It could chine walk pretty easily while trimmed out. I would think 90 HP would be pretty wild. Not impossible, but caution should be exercised at higher speeds.

Doug

Posted by ioptfm on 02/22/08 - 7:10 PM

I'm not sure what end result you are looking for but I would think twice before I bolted a 90 on a 15. Weight factor would be a big concern and I would imagine at WOT it would be very squirrly and unstable. I have a 60 on mine and at WOT it is skipping along pretty quick. I would venture to guess that you would probably get better performance out of a 70 vs a 90. Top end and out of the shoot.

Posted by sfergson727 on 02/23/08 - 9:21 AM

Mine runs over 40 mph with a 70 HP Johnson, and it can chine walk at that speed. I would not even consider putting a larger engine on it. BTW, if you are boarded by the coast guard with a larger engine than the data plate specifies, I believe you are in for a ticket, and possibly prosecution for careless/reckless operations. Don't know this for a fact, but I would consider it before putting the engine on.

Posted by kamie on 02/23/08 - 2:54 PM

sfergson727, you are not violating any federal law by powering with an engine of higher HP than shows on your capacity plate. You may be violating state laws, but not federal and as such the CG won't give you a citation for overpowering.

Posted by cajanwhaler on 02/24/08 - 6:28 AM

#11

My 15 came with a 1979 85 Rude and still runs well, when the ole gal gives up I will go with a 70 due to gas prices. She is quick but the weight , gas prices and noise
makes me want to go 70 hp.

Posted by fitz on 02/24/08 - 7:20 PM

#13

I'm in the 15' with 90hp process right now.
When I pulled off the 70 Evinrude I found a half rotted transom, I just finished with a "SEACAST" retro and it's very strong. If the transom had been OK I would of still hung the 90 as planned. The Whaler 15 can deflnitely handle 20 more horses, especially with a Yamaha 90, 261-lbs, it only weighs 11 pounds more than a OMC 70 which origlnally this boat was rated for. I'm sure my Seacast transom could handle a V-4 now, but she would sit too low in the water. My Yamaha will mount to a 5" manual jackplate, battery and fuel moving forward.
I'm at a point that she's ready to put together!

Edited by fitz on 02/24/08 - 7:58 PM

Posted by MW on 02/25/08 - 1:55 PM

#14

I don't "think" it violates "Federal" USCG law but, the USCG does strongly advise against "Over powering" a Hull past it's max rating, It may however violate state reg's., and you may be in violation of that, which may get you a ticket from marine enforcement, The "Capper" is when/if you have an accident, an over powered hull leaves YOU "Wrong" right off the bat. Most outboard places will sell you what ever type of engine you want, they draw the line however, when it comes time for the installation of the motor on the hull, rarely will they install an engine over rated for the hull because, it leaves "THEM" liable in case of an accident. Getting the boat insured could be a problem as well.
mw

Posted by Bob Kemmler JR on 02/25/08 - 3:43 PM

#15

I run a 90 on a 15 Mischief, see's over 50 mph with no sign of chine walk. I'm thinking of selling the 90 in favor of a 150+. 90's no big deal, you don't have to floor it all the time and the motor will hardly work hard at all.

Posted by Bob Kemmler JR on 03/02/08 - 4:53 PM

#18

Never know a 200 or 250 weighs the same as a 150 ;) I have a buddy offering to yank the 280 race Merc off his stv river rocket just to see the looks on peoples faces when we cruise out to the local sand bar on a sat or sun :D That thing sounds MEAN too.
I have given thought to selling the Mischief and the 13 and just getting down to one boat. the 21 will probably be the most often boat used when done and it would be less headaches for me all around as a single boat owner. Hard to tell though? I sure do love that red mischief. There would definately be footage of a V6 on a 15 footer, hopefully it wouldn't be used for my eulogy :D

Posted by Binkie on 03/03/08 - 4:02 AM

#19

Bob, I always look at it this way, If you ain`t skeered, your not having fun!! The problem is In order to get folks to go out in my Bass boat with me, I have to promise to keep the speed down. Its no fun at all.:(

rich

Posted by Bob Kemmler JR on 03/03/08 - 4:03 PM

#21

I'm sure with a V6 on the boat there would be quite a few skeery thrills :o Sorry I missed ya Rich, this weekend was just too darn hectic for me. I'm sure we'll meet up this coming spring/summer at one of the Whaler gt'gs, maybe I'll have my 21 all finished. I go back and forth on selling the 13 and Mischief, we'll see. I just hate the thought of letting it sit in the shop and not using it constantly.

Posted by sraab928 on 03/03/08 - 4:56 PM

#22

I know the feeling Bob.. but then you have to ask - is it costing you much to keep it? Would you miss it? Could you get one back in the same shape for the same money down the road? I think I will probably have my 13 for a very long time. Its a timeless boat thats built like a tank.

I know in the end you will make the right decision for you and your wife. Hope your enjoying your Florida sunshine... we hit 60 degrees in NJ today - looking at 70 tomorrow.... Lovin every minute of it.

Posted by onig on 05/01/08 - 2:57 AM

#23

90hp on the 15" would be just perfect, I think that 90hp should be the HP limit
for the 15" whaler.
I've had a 200hp Merc shortshaft on my Mischief, gets to 60mph in less then 20 seconds...
after that it becomes toooooo dangerous..i once got 65 mph but very scary,
I think thats the "HUllSpeed" of the mischief...!!!!!

90hp on a 15", GO FOR IT, lot of fun!!
[img]http://www.geocities.com/gsprockel/Gmischief1klein.JPG[/img]

Edited by onig on 05/01/08 - 6:27 PM

Posted by Binkie on 05/01/08 - 5:58 PM

#27

I wasn`t aware the 2.5 Merc XR series Mercurys came with a shortshaft 15" mid and standard gearcase. What gearcase are you using. have only seen them on OPC tunnel hulls Formula 1 boats.

rich

Posted by onig on 05/01/08 - 6:49 PM

#28

It's a 20" mid sec. carbed 200 hp early 90's lower unit and a '94 powerhead.
Actually, I did this in the summer of 2005...
But we have very rough sea there around the Island...and it was a blast to drive on calm waters, but in rough seas... not very !
When tippin in the throttle after some air time..you could feel the boat like twist/pull to one side...(engine torque)...
So I took the Engine off and sold it....
I also had a 22foot RIB powered by 2x 115 hp Yamaha O/B.
HAd too much trouble with it...leaks all the time...so I sold that one too(early this year), without the engines.
So now 1 of the Yamaha 115hp will power the mischief...
It will not be as much fun as the 200hp Merc, but it will sure be more driveable
in rough seas....!!

I dont have GOOD quality pictures here as I am in europe right now,(Studying).
I do have a small video clip, I'll try to put it up Youtube tomorrow.
Greetzzzz
G
[img]http://www.geocities.com/gsprockel/Gmischief1klein.JPG[/img]
[img]http://www.geocities.com/gsprockel/Mischieff.JPG[/img]
[img]http://www.geocities.com/gsprockel/mischiefff.JPG[/img]

Edited by onig on 05/01/08 - 7:13 PM