Check out this thing! 23' Seacraft 600hp 96mph!

[flyingfrizzle]

Originally Posted by drtyTshrt

FF I have a 20ft center console with a 400lb 200 Merc with a worn out 14" 19 pitch SS prop and get 48 at WOT bout 6800 RPM.

I need a new prop and I would like your suggestions.

I have been told the bigger diameter props for the 2.5 liter and four strokes are to big for my 2.0 liter.

I want to be in your range 48 mph at 2/3 throttle.

I know with my prop being worn so bad is increasing the RPMs a lot but I also think I may can do a 21pitch.

Suggestions please.

I would prop to the next pitch to get you rpms down some if you don't normally run heavy loaded sometimes and also stick with the small dia props 14.5 inch or so. The 2.0s don't like the big 15.5 inch plus cupped wheels so well. My 200 is a modified 2.5 with an aftermarket Brucato computer box and some other mild items done to it. Nothing to rad but it may put out 220-230 hp or so vs a standard 200. I found out for faster top end speeds the smaller and lighter 14.5 inch props with give you more MPH. The mercury 40 or 41 series style are lighter and faster than the newer 44 or 45 Plus series with vent holes. The mirage plus props at 15.5 do much better far as handling, keeping on plane, lifting the rear and cupping the water in ruff conditions but will lose you 3-5 mph. Like mentioned I have ran chopper surface props and also the rev four mercury prop, getting you motor height right and the lower unit out of the water so the AV plate is visible while under way not dragging will help you more than most props as you don't have the drag. You may pick up more with adjusting the motor than changing props. Also my hull is super light with only the necessities, less that 30 gallons of fuel and no seating or any other add-ons. I never finished out the hull as I started other projects so how much you load the hull will effect you too. Start with getting you motor height right, get the right pitch to match RPMs so that you can hit max limit or slightly above with your self and normal load, then you can try different prop types. The 3 vs 4 blade you may need different pitch as a 19 four blade may act as a 17 three blade. Also try to move weight forward and balance the boat out best you can.

[69Seacraft20]

What!? The 20 has a hooked stern hull?

[DonV]

Hey Mike, Dave has his Seavette for sale, ask Sandy if it's fast and fun!! No Shoie required.

[Offshore Asset]

I've seen a video of that boat doing 80. I'll have to find it

[bgreene]

Originally Posted by Offshore Asset

I've seen a video of that boat doing 80. I'll have to find it

Would like to see that ......80.........with a lot more left to go !

[Outrageous]

I love fast and love my SeaCraft but 85 or 90 +. I wonder what they have for insurance if any?

[DonV]

Actually he will have no insurance if he makes a claim and the insurance company finds out he was over powered by about 300 to 350 hp from the original manufacturer's limits. Funny how insurance companies will take any information you give them about your boat as true, max power sticker, etc. when you purchase the insurance, then if you have a major claim out of nowhere they know all about your boat's limits. Years ago I had a friend who re-powered his boat and was over powered by 25 hp over his capacity sticker and original insurance application, 175 hp vs 150 hp, hit a oyster bar and tore up the engine, hull, etc. and they told him tough crap, thanks for your premiums. I remember him telling them he got a real good deal on the 175, the agent said "not really"!

[Outrageous]

I know someone who was denied a claim when towing in excess of rated towing capacity. The boat came off the trailer at highway speed ripped the drives off, ground the bottom down to the bone before it slid into some guardrails. If they can find a way out of paying they will.

[drtyTshrt]

Thanks.
That is all good information and I have realized about all of it before I posted the question.

I did not know about the 40 and 41 series props so you gave me something to research.

Thank you again for replying.

[flyingfrizzle]

Originally Posted by drtyTshrt

Thanks.
That is all good information and I have realized about all of it before I posted the question.

I did not know about the 40 and 41 series props so you gave me something to research.

Thank you again for replying.

Yea the older 40 & 41 props are lighter and have thinner blades where as the newer Plus props have thicker blades that flex less and are less prone to cracking. There is give and take. Thicker blades are stronger and don't flex as much but the lighter ones are faster!