115 too big?

[Jesseleey]

I have a '74 glastron-carlson CV 16, its a 16ft boat, and I am pretty sure that these hulls are rated for a 150 hp. But it seems like the 115 I have on it just is too big? Does anyone have any kind of info for that? Thanks!!

[Frosty]

I think I am right in saying that the Glastron Carlson did once hold the jump record for speed boats. I think I am right in saying also that this was the boat used in the James Bond movie in Venice. I also think I am right in saying that 115 is not too big and a bigger one would be nice.

[Ari]

115 H/P for a 16 footer speed boat is real nice.I don't know about the brand you are talking about but I used to have a 140 for a 16 footer.If your hull is deep v, it is a lotsa fun boat.

[sandy]

Originally Posted by Frosty

I think I am right in saying that the Glastron Carlson did once hold the jump record for speed boats. I think I am right in saying also that this was the boat used in the James Bond movie in Venice. I also think I am right in saying that 115 is not too big and a bigger one would be nice.

Glastron literature identifies the Live and Let
Die boat as a GT150 with a Evinrude Starflite 135hp engine.The year was 1973.
Interesting to note is that the '73 catalog lists the max hp of the GT150 at 90hp.

[hmattos]

Manufacturers power ratings are often based on three issues.
1) How will the boat handle at that speed
2) how will the boat float when stationary and loaded with such a weight on the transom
3) how strong is the transom to accomodate the two major loadings - wave jumping thrusts and road loads on the trailer when on rough surfaces.
In my experience the greatest damage to transoms happens when the boat is on its trailer!
Remember that 2 and 3 need to be revised as the years go by as the engines delivering, say 115 hp, are much lighter now than they were 20 years ago. I am talking Evinrude ETEC here, not fourstroke.
Hugh Mattos
Chartered Engineer
www.explorermarine.co.uk

[Jango]

If your 115 is the inline 6 cyl. Mercury (1150), I read someware the motor is way under rated. It is putting out someware around 150 HP, which should be just about right for your Boat.

Jango

[Fanie]

From my experience -

Fit the biggest motor your boat can handle (carry without sticking it's nose in the air). You'll have to use some self control though and know how to use the power trim and tilt. You don't drive your car as fast as it can go all the time, it's the same with a boat.

You could balance your boat better by moving fuel tanks and batteries more to the front, same with seating. Seating normally works well about 1/3rd brom the back.

If you doubt the transom, replace it. It's no joke if a 115 takes off elsewhere with part of the boat attached to it. I've seen it happen on a smaller boat and motor once. The motor overtook the boat to the horror and disbelieve of the people in the boat, and wonderously stayed upright for about 50m before it died and sunk. I guess it ran out of fuel. I won't take the chance with a doubtfull transom. There are core materials available that is suitable to make a lighter transom from, thick laminated transoms are heavy.

I doubt the motors would have become that much lighter to make a real difference.

[Frosty]

I have to agree with fanie. I once fitted a 150 merc to a boat with a max 80HP plate on it. I sold it to my mate who put a 200 HP on it. What a ride and what a tow. With a 17 inch prop it would out pull as good as the Mastercraft Just don't go pulling ski jumps around with it, or if you do respect the power you have.

It was simply a case of the manufacturers not knowing what they were doing. The transom was massive with a good well glassed in. It never showed any signs of cracks.

At 30 MPH I would assume the economy to be similar.

[blared]

I always like big engines on small things, makes it easier for the engine too . Don't be scared, you will get used to it or you will miss your 155.