proper motor placement

[vdubman68]

i just bought a 14 foot starcraft fishing boat it has a 21 inch transom my motor is only a 5.5 johnson. the motor doesnt stick below the boat im wonderng if it should . the boat moves along ok but seems to skip when you really crank it up like its sucking air.

 

[mthieme]

Re: proper motor placement

When you say it doesn't stick below the boat, you mean the cavitation plate doesn't reach the bottom of the boat?

 

[fiftiesoutboards]

Re: proper motor placement

It sounds like you've got a short shaft on a tall transom. When you go slow, the prop has enough water, but as soon as you start to plane, it is 5 inches too high out of the water. You could modify your motor to make it a long (20inch) shaft, but you'd be better off selling it and finding a 15 horse long shaft. The extra power will allow you to plane three or four adults, and will still troll nicely for fishing. 50's

 

[vdubman68]

Re: proper motor placement

When you say it doesn't stick below the boat, you mean the cavitation plate doesn't reach the bottom of the boat?

yes the cavitation plate is above the bottom of the boat actually the bottom of the motor is even with the bottom of the boat

 

[mthieme]

Re: proper motor placement

Argh. I'm surprised the water pump impeller is still working.
Yep, definitely a short shaft motor.
You either need to get a long shaft motor (20") or cut the transom down.

 

[tashasdaddy]

Re: proper motor placement

agree with mthieme .

 

[canuck_eh]

Re: proper motor placement

I actually just had the same thing happen to me. Bought the boat and motor as a unit and found out about getting "short shafted". In the long run it turned out for the best as I sold the outboard and hull separately and made a $50.00 profit.