Bike or sled engine would be best anything 200CC + would be great. Good Luck!
Sled engine? How much do you know about Australia Solomon?
Fowler, I too live in remote areas of Western Australia, I feel your pain about finding parts.
A 13hp engine would be fine, if you mean a torque converter from a motorbike or scooter then you'l most likely need to machine an adapter to make it fit (you'l need access to a metal lathe and a milling machine for that), if you mean a torque converter made for an industrial engine(like your Honda) then it should just bolt up(providing the shaft is the right diameter). Torque converters for industrial engines are **** expensive in Australia,
The Edge Products is probably the best place to get one new in W.A, they sell the Comet 40 series(suitable for you engine) for $490, yeah, abit pricey.
Your best option is to get a motorbike engine, way more power, a real clutch and gearbox probably cheaper ect ect.
But as brendonv says, just about any engine is okay though.
Thanks
Hayden