Custom outboard - (crazy) idea ....

[iGrf]

ok hear me out, I just came up with this crazy idea.

The boat we just bought has a 5.5 1956 johnson outboard, this is a short-shaft engine with R-N-F gears etc.
We don't like it because it's too short and it has this pressurized fuel tank which I'm scared of.

In our sailing club we 'found' a 4hp johnson (1969) long-shaft engine without a gearbox (so it's always in forward gear).

The idea I now have is if it wouldn't be possible to combine both engines into one.

Basically making the shaft of the oldest engine longer and using the fuel pump of the newer engine to get rid of the explosive fuel tank.

OR

moving the 'gearbox' to the newer engine.

Does anyone know if this easy to do, remotely possible or just a crazy idea

 

[Scott Danforth]

Re: Custom outboard - (crazy) idea ....

not sure if the two can be combined, however converting from a twin line pressure tank to a single line has been done many times.

 

[oldcatamount]

Re: Custom outboard - (crazy) idea ....

Crazy idea. You're asking for trouble. My suggestion: sell the two motors, use the money for a motor that fits your needs.

 

[raczekp1]

Re: Custom outboard - (crazy) idea ....

i think in both engines equal parts is only ignition plate and bolts.
it esay to convert to single line.
http://www.sschapterpsa.com/ramblings/Converting_dual_fuel_line.htm

 

[Chinewalker]

Re: Custom outboard - (crazy) idea ....

Throw enough time, money and effort at anything and you can probably make it work. But, it would be ugly and likely prone to failure. I agree with above - sell them and get what you need...

 

[BonairII]

Re: Custom outboard - (crazy) idea ....

Crazy idea. You're asking for trouble. My suggestion: sell the two motors, use the money for a motor that fits your needs.

I agree. No sense in throwing a bunch of time and money into a 5.5 hp motor.

 

[RogersJetboat454]

Re: Custom outboard - (crazy) idea ....

Sounds like a good way to trash 2 potentially good outboards. As others have suggested either sell both motors, or find the correct lower unit for the 4 HP.

BTW, the pressure tank explosion phobia is a bunch of bunk. Hundreds of thousands of people have used these older outboards with pressure tanks, without incident. I would be willing to bet tens of thousands still do. The only draw back to the old pressure tanks are the aging pump mechanism on the tank, the potential for rust in the tank, and locating affordable fittings for the tank. I would have absolutely no qualms about using one of these "bombs" as long as it is in working order.

 

[BonairII]

Re: Custom outboard - (crazy) idea ....

I would take far far more pressure than an outboard could generate to cause a fuel tank to explode. The fuel lines, gaskets etc would split long before any dangerous pressure levels could be attained.

 

[Huron Angler]

Re: Custom outboard - (crazy) idea ....

I'm with Roger and Bonair, I have very little fear of my old pressurized tank exploding.

I'm much more worried about not catching any fish or running out of beer

You could order a fuel pump and convert without salvaging parts from the 4hp.

Search in the OMC outboards forum for "fuel pump conversion" and you will find great info.

 

[iGrf]

Re: Custom outboard - (crazy) idea ....

I'm much more worried about not catching any fish or running out of beer

I'm from Belgium so running out of beer would be a huge disaster

Anyway it's not only the fuel tank that's holding me back from using the 5,5hp outboard, biggest issue is the fact that it's too short.
the prop is only just below the waterline.
Any waves and it gets into trouble.

 

[Daviet]

Re: Custom outboard - (crazy) idea ....

Would you be able to cut down your transom to fit the engine?