Seven Marine 627 hp outboard

[bgreene]

All the discussion about best fit for 23' Sceptre.......twins 150's, 250, 300 hp

I'm thinking ONE of these and the boat becomes a " Super Sceptre."

Ok so at a bit over 1,000lbs somewhat heavy, but proper transom can handle.

Performance............now this is the fun part:
Cruise.....................maybe 45mph at 4,000 rpm ?
Fast cruise...............maybe 55mph at 4,500......
WOT.......................maybe 70mph +.....wide open, trimmed and tab'd just right.

How would it ride ? I'm thinking wow.

[FLexpat]

My 5.7 Bravo 1 I/O is just over 1000 lbs so I'm thinking the balance wouldn't be very far off. 627HP just might get it fast enough to chine walk a bit... I'm thinking more like 80+ if it doesn't start dancing first.

[Blackfin26]

The 2009 Seacraft 26's were designed to go 65 with twin 250 Verados.

[bgreene]

Originally Posted by FLexpat

My 5.7 Bravo 1 I/O is just over 1000 lbs so I'm thinking the balance wouldn't be very far off. 627HP just might get it fast enough to chine walk a bit... I'm thinking more like 80+ if it doesn't start dancing first.

Humm..... I gained approx 8 mph with 50 extra hp....so let's just figure 15 mph per 100 hp.
With 300hp, I believe Scepter runs about 50mph. Since the rule of " diminishing returns " kicks in, speed increase per 100 hp will yield less.... but, fair enough even at 10mph per 100, 80mph seems possible !! ( assuming of course the hull can handle)

In sailboating, there's a term called " hull speed" meaning no matter how hard the wind blows, that hull will only reach approx X mph.

Seems the older 23 was a hull capable of speed.

[flyingfrizzle]

I have seen pictures of 23's with twin 225's and twin 250's and the owners tend to say that after 65 they get scary as hell. The one guy with twin opti 225s said he got his up to 68 and that was with 8 people on board. He also said that with just him he never got passed 63. The weight kept it in the water and kept it from walking all over the place. You will never go safely over 70 in this hull with out major modifications. A motor like this would work good for an half throttle cruse of 60 plus but past that the top end would be wasted. Now from stop to 60 with the handles dropped would be one hell of an ride.

I think kmoose actually had twin 250s on his and he may can give you some actual experience. Im just going off what I have been told.

[Snookerd]

I had twin 225's on a bracket on a 23 SF. I was at three-quarter throttle at 60. Doodlebug had twin 250s on his Sceptre.

[Bigshrimpin]

Originally Posted by flyingfrizzle

You will never go safely over 70 in this hull with out major modifications. .

x2!


Bgreene - 23 seacraft is a kick ass fishing boat . . . no need to try to make it into something it's not If your objective is to go fast (above 55 - 60) there are much better hulls to work with than a 23 and power plants that have a superior power to weight ratio than seven marine engines.







see the nice pad on the Allison ^^

[gofastsandman]

Originally Posted by Snookerd

I had twin 225's on a bracket on a 23 SF. I was at three-quarter throttle at 60. Doodlebug had twin 250s on his Sceptre.

Doodlebugs rig was so stern heavy he had to power load
getting off the trailer.

[kmoose]

Previous owner of my current sled......

[ericallen01]

Great discussion - I am running twin 2.5L Mariner 175 hp on a Gilbracket my 1973 Tsunami. It's been up to 60 - engines keep the boat weighted down - but it's a bit fast for the hull. Runs nice at 45-50, like the twins in a big following swell for stability.