1984 23 Seacraft Sceptre Hard top

[diver429]

I bought this boat down in Point Pleasant NJ back in May , 2008. It has a 200 mercury optimax outboard on a full transom armstrong bracket. The boat according to seacraft specification weighs 3150 lbs. The boat at 5400 rpms runs 35 miles an hour. I have to run the boat at 4600rpms just to go 25 miles an hour. Do these numbers sound accurate to you guys. It also has a 100 gallon tank which I dont fill. I usually leave not more than half in the tank. I would like to put a 250hp 4 stroke on the bracket but I am concerned about the weight. I definetly think the boat is under powered at this time and I hate to run at such high rpms. Between the 2 motors there is a 80 lb difference. Does anyone have a hardtop with a outboard bracket with a 250 hp 4 stroke on it. If you do what speeds do you run at, meaning wide open trottle and at cruise. Thanks for any input in advance. Peter M.

[Old'sCool]

250 Yam 2S on bracket here. The prop is one variable. 17P Yam. SS 3-blade pushes mine low-mid 40's flat and light.

[riptide]

I was out today blackfishing on Sandyhook reef on my 77 Sceptre. 70 gal of gas,3 pob ,full canvas enclosure.225 carbed merc.4700 rpm 34 mph 20.5 gal per hour,ouch
Mirage plus 15" pitch prop.
Boat needs more power
Plan on repowering w/300 hp suzuki soon.

[ScottM]

pmtautog,
Your performance #s are similar to my father's '82 running a '97 225 carb'd Yamaha. He cruises about 27 @ 4600 and WOT 39-40 @ 5600. The hardtop is probably slowing you down a bit but I wouldn't consider your boat underpowered. You want to talk underpowered? My '78 Grady 20' WA runs an old carb'd 115 Evinrude and gets 28-30mph WOT.

makoman,
If 4700 is WOT, it sounds like you need a different prop. If that's a cruise #, you're doing really well except for the fuel consumption, which leads me to believe it's a WOT #.

[diver429]

Makoman I know your not doing 34 miles an hour cruise with a 225 hp on that boat. If you are doing 34 miles an hour at 4700 rpms then like scott m said you need a different prop. That motor at wot should be between 5200 rpm - 5750rpm according to your manual. My boat is just a little unpowered I would prefer a 250 hp because then the motor doesnt have to work as hard and I would get more life out of it. I tried a few different props and now am running a 14 3/8 x 15 an getting 5400 rpms. But I took a measurement from the bottom of the boat to the sced on the motor and it looks like I can raise it another inch higher on the bracket, which would then increase my rpms between 200-300 rpms. Thanks scott m for your input.

[gss036]

There is something wrong with those numbers, I ran a 14 1x2 X 17 SS w/slight cup on 23WA and would trun 5400 trimmed out and close to 44 mph depending on the water. Try a different prop.

[riptide]

pmtautog,my WOT is 5500 rpm at about 42 mph.The numbers I posted was just what I was cruising at that day.I went from a 14.5x17 Vengence to a 15.75x15 Mirage plus and all my numbers improved but she is still a gas hog.

[diver429]

Gary was that with a 225 or 200 hp. And was that a 23 seacraft wa and what year was that, because when sea tracker took over the seacraft mold in may/1985 they made the boat a little lighter. But if those numbers were with a 200 hp 2 stroke Im willing to try another prop.Thanks Peter

[gss036]

Those numbers were with a 1989 200 Hp carbed Merc. It is a 1989 Seacraft 23WA. I still have the old aluminum prop laying on the shelf and nothing to use it on.
I just repowered with a Honda 225 and get about the same speed, also installed a fuel flow meter but have tried it out yet.

[diver429]

Gary was that motor on a bracket?What numbers were you getting at a cruise with the old mercury motor. Would you be willing to sell that aluminum prop or be willing to let me try it on my boat? I ll pay for shipping and handling. Also do you know the numbers on your 225 honda at cruise, and at wide open throttle. And what size prop are you using with the honda. Also what is the weight of that boat. Thanks for your input in advance. Peter