best propellor
 

Hi there.
I am thinking of starting a "club .90 racing class" where we could have a reasonably quick boat which does not cost the earth and uses cheap motors.
SETUP:
I have a nitro .45 racing GRP hull which is similar to a unbuilt 35' Silak and I have a N.I.B. ASP .90M marine engine and tuned pipe. I am thinking using a flexi-shaft and 1/4' extended surface drive, but I was wondering if it is even worth doing this project and what size propellor would you recommend?

Does anyone have any videos of any ASP powered boats?
Many thanks
rinkhals01

You would have to start a local class where the folks can all still buy the same size / brand engine.
Current search I can only find them here and the largest is the:

ASP 0.46m

https://www.justengines.co.uk/acatalog/A.S.P._Marine_2_Stroke.html

Thanks Pond Skipper great advice Sir.... makes good sense.

Something else you have to consider is that 90 is twice the size of engine that boat was built to handle. To give you and idea of what you would be looking at, it would be like pulling a factory installed 1.5 liter engine out of a car and dropping in a supercharged 6 liter. The car frame might not carry the weight and might twist as soon as you put your foot on the accelerator. Then, of course, you would also have the problem of being able to carry enough petrol to give your car a decent range. All these things are the same as what you would have to deal with dropping that 90 into a 45 sized boat. It might not be able to handle the weight, might barrel roll when you hit the trigger and may not carry enough fuel to run for more than a minute or two.
Just out or curiosity, do you know any of the people that race boats in NZ? I know of a guy, think he's on the northern island, that's pretty good with race boats