Modify outboard motor to power an Iceboat"

[Icefisher]

I posted this first under "diy marinizing" and thought this thread would be better.
Please forgive me if Ive broken some rule in doing this. Thanks.

This may sound insane, but back in about 1969 or 70 I rode in an aluminum boat over a frozen lake, powered by an outboard motor whose "prop" was a large toothed disk (much like a circular sawblade, only larger) that dug into
the ice to push the boat along. Naturally, the disk turned perpendicular to a normal outboard propeller. Steering was just with a standard tiller arm.
This thing worked amazingly and was very very fast !

My question is this.... Can someone explain how an outboard can be modified in this way? Can a propeller shaft be "turned" 90 degrees?

[kenJ]

It all depends on how the top of the motor is attached to the output shaft. It the power head is bolted to the lower half, it may be possible to rotate it 90 degrees to do what you describe. If the bolt pattern doesn't match, you may need to devise an aluminium plate to bolt the pieces back together.

[TerryKing]

Originally Posted by Icefisher

..(snip).. Can someone explain how an outboard can be modified in this way? Can a propeller shaft be "turned" 90 degrees?

I think the bigger problem is how to cool any typical water-cooled outboard when there is no source of (liquid) water available..

A small air-cooled outboard, or a small air-cooled 'lawn tractor sized' horizontal shaft engine could belt-drive a disc...

Or a snowmobile drive system could be adapted....

[kenJ]

Good point Terry. The set up he saw was probably just making use of the drive system. Would definitely need to be air cooled.