Adding gas engine to 4m electric boat

[kirtley]

I have a nice little 4m boat (http://www.electraboat.com/) that runs on electric - about 350kW motor (i.e. 0.5 Hp). Obviously, speed is limited so I am wondering about adding a small (3Hp) gasoline motor (http://www.cqwolei.com/ProductShow.asp?ArticleID=134). I guess this should double my speed so I can use it for short blasts to get where I want to be then switch back to electric. Do you think this is feasible? How would you connect the two motors (the electric system is a simple parallel belt drive (http://www.electraboat.com/electric-boat-engine-2.jpg) - I will take out one bank of batteries and install the engine there) so that I can switch easily between them? Are there any dangers I should be aware of?

[gonzo]

The photo doesn't show the belt arrangement. A second electric motor or a bigger one would be an easy fix.

[kirtley]

Yes, thanks gonzo! I was also considering that. Here's a better picture:

http://www.electraboat.com/electric-boat-flotation-2.jpg

I actually have 2 more of the same motors, so I guess I can just try mounting them parallel, with a belt joining them, or run another belt independently to the prop? Which would be the best arrangement do you think?

Thanks for all the help - I'm really glad I asked now!

[gonzo]

Ideally, you should be able to diconnect it to prevent friction losses and extra wear. An A/C automotive clutch could work.