Moderated Discussion Areas
  ContinuousWave: Whaler Performance
  115 on montauk

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   115 on montauk
harry posted 10-30-2002 09:09 AM ET (US)   Profile for harry   Send Email to harry  
could someone comment on positive and negative preformances issues if I place a 115hp 4stroke on a boat rated for a 100hp (1987 montauk )
OutrageMan posted 10-30-2002 10:06 AM ET (US)     Profile for OutrageMan  Send Email to OutrageMan     
Two things...

1) The 115 four stroke will probably weigh to much for the boat.

2) My father had a monatuk with a Johnson 90 on it. With the two of us @ WOT the boat began to get a little squirrelly.


NoviceWhaler posted 10-30-2002 12:19 PM ET (US)     Profile for NoviceWhaler  Send Email to NoviceWhaler     
Not to mention that this exceeds the HP rating for the Montauk (100 HP) which may cause legal and/or insurance problems depending on where you live and your particular insurance carrier.


jameso posted 10-30-2002 12:28 PM ET (US)     Profile for jameso  Send Email to jameso     
Had a LES (commerical) Montauk with an OMC 115, 2s. Great rig, Much more responsive and a bit faster than my buds Newport with an OMC 88 on it. Don't know and can't comment on the weight of the 4s.
Yeah, Yeah I hear the lawyers already.
My 02, Jim Armstrong
JBCornwell posted 10-30-2002 12:43 PM ET (US)     Profile for JBCornwell  Send Email to JBCornwell     
Hi, Harry.

As far as I know, all of the 4S 115s weigh a bit (or a lot) over the 400lb transom limit for the classic 17 hull that BW issued last year.

Good luck.

Red sky at night. . .

Bigshot posted 10-30-2002 12:47 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
I think toooheavy. The 70 4 strioke I have now is about pushing the weight limits. Remember it is only 16'7".
tabasco posted 10-30-2002 01:19 PM ET (US)     Profile for tabasco  Send Email to tabasco     
Works fine on the new Montauk 170 but too heavy for the classic model.The weight is the same as the 90HP 4 stroke 386 lbs. Think if you want a 4 stroke on a classic go with Bigshots set up.
tabasco posted 10-30-2002 01:21 PM ET (US)     Profile for tabasco  Send Email to tabasco     
Insurance is NOT A PROBLEM. Progressive will cover the boat with an over HP rating.
Tom W Clark posted 10-30-2002 01:31 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
How much does a 115 hp four stroke motor weigh? The published maximum engine weight for a classic Montauk is 410 pounds.

Whaler did not even publish a maximum engine weight for any model until 2000 and did not have that specification for the Montauk until 2002.

The maximum engine weight specification has nothing to do with the safe running performance of the boat nor does it have anything to do with the strength of the transom. It is purely a waterline issue and an effort by Whaler to keep water out of the boat by keeping the transom a reasonable distance above the waterline.

I know from personal experience that a Montauk with 360 pounds of motor on the transom and a battery in the stern is no problem at all.

If a 115 hp four stroke motor really does weigh only 386 pounds then there is not going to be any problem with that.

As to overpowering a Montauk, itís commonly done with 115 hp motors. Nobody says you have to run at full throttle anyway. Insurance may be a hurdle, but not one that cannot be easily overcome.

thebone12 posted 10-30-2002 02:50 PM ET (US)     Profile for thebone12  Send Email to thebone12     
what about a the new 115 ficht, or 90 nissan/tohatsu 90 Lpdi,
Bigshot posted 10-30-2002 02:51 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
I think that 386lbs is pushing it but yes...should not be a problem. The yamaha 115(401), Honda 115(500lbs) and the Zuki 115(416) are all too heavy. The only 115 I would do would be the Merc if it weighs 386 but add a SS prop and you are over 400lbs, etc. My 70 at 338 sits about 3/4 inch lower in the rear than the 260lb Yamaha it replaced. Add another 50-70lbs and I dunno.
JBCornwell posted 10-30-2002 02:58 PM ET (US)     Profile for JBCornwell  Send Email to JBCornwell     

The 356lb 90hp Merc 4S is a carbed engine, like the 100hp Yamaha.

The EFI 115 Merc or Yammy weighs 400lb. Either that or they found a way to make the Merc leg 14lb lighter.

The Suzi/Johnson EFI 115 weighs 415lb.

I have the same package that Bigshot has, and agree that the DF70 EFI at 336lb is plenty for the 16.

Red sky at night. . .

tabasco posted 10-30-2002 06:45 PM ET (US)     Profile for tabasco  Send Email to tabasco     
May I suggest that you go to the their web site:

You will see that both the 90 HP four stroke and the 115HP four stroke weigh 386 LBS.

lhg posted 10-30-2002 06:49 PM ET (US)     Profile for lhg    
On the Yamaha built Merc/Yamaha 115 EFI's, Mercury does use a lighter lower unit, and the engine weighs the same as the factory installed Merc 90 4-strokes, 386 lbs. You COULD buy a Classic Montauk with a Merc 90 4-stroke engine. So engine weight is not an issue.

Yamaha's 115 4-stroke is heavier because it uses a V-6 gearcase and larger prop, so that the V-6 Counter Rotation can be offered. Nobody makes CR lower units in the mid-size 4 1/4" gearcases. Mercury's version of the 115 does not offer CR, hence a smaller gearcase and less wieght. My guess is that a Merc 115 would be a great engine for the older Montauk. Expect to go over 50, and it could get squirrely. You will rarely need the extra HP, but to get the EFI is reason enough to get the 115 over the 75 or 90. You don't have to run it wide open!

JBCornwell posted 10-30-2002 07:21 PM ET (US)     Profile for JBCornwell  Send Email to JBCornwell     
Hmmm. I have Merc literature that says that the 4S 90 weighs 356lb, other pubs say 386lb.


Suzuki has pubs that say that the DF70 weighs 336lb, yet Bombardier says it weighs 356 with Johnson decals on it.

Mine weighs 337lb with a SS prop installed.

With so many conflicting specs, maybe we ought to settle for "heavy" and "heavier". :)

Red sky at night. . .

rolfwoods posted 10-30-2002 10:22 PM ET (US)     Profile for rolfwoods  Send Email to rolfwoods     
I have a 1997 Merc 115 on my 1978 Montauk. The battery is mounted in the consol. It doesn't sit considerably lower in the water than it did with the old Merc 70. It runs 48 mph +. A little squirrely at WOT but the reserve power is never realy have to work the motor.
dogfish2 posted 11-01-2002 01:36 PM ET (US)     Profile for dogfish2  Send Email to dogfish2     
All things equal, I suggest you consider the Merc 115 4s, primarily for the EFI. I run a 90 4s on the Montauk and weight is not a problem as long as the battery(s), bait tanks, other heavy items, are not pushed back to the transom. The extra power is always nice to have, but you do not need to use it. Good luck with your decision.
lhg posted 11-01-2002 04:58 PM ET (US)     Profile for lhg    
One of the things these engine manufacturers like to do is show the weight for the lightest version of an engine, say a 20" shaft vs a 25" shaft. Is prop weight included? Who knows, since we can't lift these things up to weigh them very easily! Could be that they're all "weight conscious" with the 4-strokes, so fudging the numbers would not suprise me. But I did always know those Johnson decals were very heavy!

This summer, in the San Juan Islands, I saw a recent white Montauk sitting perfectly alright in the water, with a 150HP Merc EFI on it, all 415 lbs of it! Have picture to prove it.

Bigshot posted 11-04-2002 10:53 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Saw a montauk yesterday with a Yamha 150hp on it.
harry posted 11-04-2002 03:29 PM ET (US)     Profile for harry  Send Email to harry     
thanks for all your comments

Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.