water cooling for a gas engine?

Hi,
I am making a 48' V hull rc boat with a 32cc ryobi engine off a trimmer. My question is: Do I need to cool it so it does not overheat? If so, I would guess that water cooling is the best option. The problem is, How would I run the cooling tubing or coil through the engine? Would I need a water pump as well? Where could I get these things for cheap?

Thanks for your help.

If you're running without a canopy on your boat you can run it aircooled as it is.Don't try wrapping tubing around the cylinder.It doesn't cool very much.A friend of mine tried it and burnt up his engine.If you have to water cool it get the fins taken off at a machine shop.Leave the fin above the exhaust port there.The cooling cap will sit on it.You can make a cooling cap or get one at www.majorsmackdown.com One made for a McCulloch should fit it.You could send the cylinder to him and he could take the fins off and install the cooling cap for you for $15 He does nice work.You wouldn't need a water pump unless you plan on letting it sit and idle in the water,assuming the engine has a clutch.