Help needed to go fast on a balloon

[Speedy Balloon]

Hi everybody, I am a newbie to the world of speed boating.

I just order a new Ceasar Thunderbolt (17 foot Catamaran Inflatable).
I will get it in about two months from now (just in time to see the ice turn to water in my area - Montreal, Quebec, Canada).

So it gives me about two months to buy the engine and figure how to do the proper setup to go fast.

The boat has a dry weight of 265 lbs and it is rated for a max of 90 HP...
The specification sheet said that the boat should reach 70 mph...

My questions are the following...
Considering that it is a very light boat,
--> do you think that it will be possible to reach 70 mph with a stock 90 hp engine?
--> to reach speed near 70 mph, will I need a jack plate / nose cone / special propeller?
--> which kind of propeller pitch would I need to reach 70 mph considering that my engine will have a gear ratio of 2.3:1 with a max 5,850 RPM?

Any help will be greatly appreciated
http://ceasar.us/yahoo_site_admin/assets/images/Thunderbolt17_FX_300.211201405.jpg

[motorheadbishop]

With that gear ratio, and rev' limited to 5850...

Your gonna need like a 32 pitch prop,

NOTE: That 90hp ain't gonna like 32* of pitch!!!:nonod:

That's if you can find one for that gear case...

If you can do a little work to it, and toss the rev limiter,

(Like fiberglass reeds, lighten fly wheel, remove oil pump and mix your own oil, etc....)

Get it to spin around 6500rpm's and 28 will get you there and

the motor/and you will like the 28 much better than the 32, for sure!!!:thumbsup:

Should not need a nose cone till about 80mph... Don't think I would wanna ride in that at 80...

Just block off the top couple holes in the water pickup and raise your motor, Water pressure gauge is a must as well!!!

Good luck!!!

[David]

Is that a 90 or 70 HP Merc triple you are thinking of? Merc used to make a thru hub cleaver that would fit, but I've never even seen one for sale. A small ear chopper would fit and these are around.