Engine query

[olley8]

I am curious if a small raft that weighs around 120lbs could be propelled by a motorbike engine? Is it possoble to have a jet propelled 125cc that will produce enough power to keep someone on board or is there a reason why personal watercraft need large engines, surely if the manufacturers lose weight on the craft, then the engine can be smaller? If anyone can help, it would be muchly appreciated.

[FAST FRED]

Every hp you put into the water will give about 20 pounds of push, a 125cc would not push hard enough for the "Thrill" most PWC folks are paying for.

FAST FRED

[olley8]

thanks fast fred for the info, what do you propose for this type of craft plus two occupants? I have been looking at the powerski website and they seem to be using a 300cc engine? Would you think that would be effecient enough for two persons?

[gonzo]

I don't think any manufacturer has any engine smaller than 650 cc

[FAST FRED]

"Would you think that would be effecient enough for two persons?"


Simplest would be any outboard from 3 HP up.

FAST FRED