23' Seacraft Sceptre with 250 Yami 4 stroke
 

What top speed would you expert expect assuming all is good with engine and clean hull, not waterlogged ?

Figure late 80's Sceptre

Seller reports high 30's to 40........... that sounds a bit slow for a fresh 250 ?

That does sound a little low. The motor might be mounted low and plowing.

I get 39 mph with an old (1988) 225 Yami 2-stroke with a light load.

I have been on two 23 seacraft cc's with yamaha f225's. Top speed is 44/45mph.

some guys use "knots (kts)"

others use statue miles....

Good point!

I have just completed a complete resto on a 73 cc 23" and used Divinicell in a lot of places to improve longevity and lighten the boat. It is going to have an Armstrong or other Bracket with either a 250 Yama or 300. Anythoughts on Bracket choice of speed with these two power options

a bracket with a tub as large as possible....hermco fiberglass bracket is the way to go

Mount it on the transom with a 10" CMC. Less weight, plenty of room, and easy adjustment. I'm running a 250 30"Zuke and it fits great.

My Tsunami is heavier than most and has seen 42 knots with a light dive load. That's right at 48 mph for those of you that drive those amphibious cars.

CMC bracket set up.... Way cheaper option as well.

Thanks for the comments on the bracket choice for my 23 ft cc. I am also interested in the performance on speed with the 300 yama if anyone has any thoughts. The boat was originally a i/o which is out and a 101 new fuel tank in the approx same place. Divinacel used everywhere for strength and right reduction with all new floor and decks. It just needed everything once we got going. I am guessing it is very dry inside and probably 300 ons lighter.
I am thinking on calm it should run in the 50's and at lower speeds run fairly fuel efficient.

300 on Armstrong Bracket
 

I put a 300 Yamaha on an Armstrong bracket with a 30 shaft. The float chamber gets the stern up to where the boat originally sat. Scuppers are dry and all original. It runs 50 mph WOT with full tank and four people.

I LOVE the way that boat sits!

More info Please. What size boat?

23' Sceptre with 30" offset bracket.

Riley... I read on another site.. Tsunami with F350 pulling right at 60mph on the Transom.

I am thinking you should be able to Prop that bugger and Double check the Running height of the AV plate. On the 23' I just sold with a 30" Armstrong Bracket I was (Cough Cough) 5.8 Inches high with a Mirage Prop on a 250 Rude.

My First thought is...that boat should be doing 55 or close too it with that set up.

Worth a look if you already haven't done that.

Robert

He's not far off with a full tank of fuel and four guys in the boat. I bet it comes out of the hole like a cannon.

Only speaking for myself, I don't put a lot of thought or effort into top speed prop selection or cavitation plate height. Cruise speed efficiency in seas and being low enough not to blow out on a hard turn rank way above squeezing a couple of extra knots out of her in the channel.

55+
 

The first time I ran the boat by myself I got 55 out of it but it only had 10 gallons in it. It felt like it would keep going too but started getting a little squirrelly!! The torque in the motor is unreal and it will throw you out of the back of the boat if your not careful.

Off subject; Moose, what does that AJ weigh?

If I remember correctly he was 128...... Almost exactly the same weight I have put on since I shot him.

Fish of a lifetime there man!!

Dug up some old photos from the day.....

Goodness that thing is a monster!! Nice Kill!!