In my younger days, when I had more time on my hands and little money, I use
a vertical shaft lawn mower engine and the lower unit off a old Johnson
Seahorse.

I mounted the engine on the keelson with a the shaft going through to the
lower unit, which was bolted to the bottom of the boat. I was using the old
outboard shaft and it ran through a home made stuffing box and a second hole
for the fwd/rev shifter shaft.

It was quite a deal and complex to operate in a 10 foot dingy.. the engine
being between the steer seat and the middle thwart. Lot's of heat on my bare
legs.

Steering was done with the normal sailing dingy rudder.

Had to be careful when running her up on the beach or in shallow water.

Sure was fun to be 'young and dumb and ....'

Steve
s/v Good Intentions


"rvbilly" wrote in message
oups.com...
Hi I am building a little 11 ft. V bottom plywood epoxy speedboat, I am
really interested in installing a 250cc dirtbike engine in it for
propulsion, I would have to use a stuffing box and shaft supports and
rudder, but I live in Chilliwack BC Canada and nobody locally can
supply parts,has anyone ever done such a install? The engine (dirtbike)
would have about 20 to 40 Hp. be watercooled with a small rad, I was
thinking I could use some kind of tranny with F,N,R from a lawn tractor
to obtain reverse in the boat, I know people have told me to use a
outboard but this is a project and I`m going to make it all work one
way or another, any help would be greatly appreciated.