15inch johnson. 30 hp.. can i uses a jack plate

[bagnallt]

Hi...
I need some advise... Can I use a jack plate lower on a 20 inch transom to use a 15 inch outboard on a 20 inch transom. I have it on there and the cavitation plate is just under 4 inches from the bottom of the transom. I was wondering if i could put on on of those ajustable jack plates and use it to lower the motor> I was told to cut the transom but i reallu dnt want to do that.
Thanks for your help.

 

[d.boat]

Re: 15inch johnson. 30 hp.. can i uses a jack plate

Hi...
I need some advise... Can I use a jack plate lower on a 20 inch transom to use a 15 inch outboard on a 20 inch transom. I have it on there and the cavitation plate is just under 4 inches from the bottom of the transom. I was wondering if i could put on on of those ajustable jack plates and use it to lower the motor> I was told to cut the transom but i reallu dnt want to do that.
Thanks for your help.

is this a primary engine or a kicker? Jackplates are used commonly to lower kickers. I don't know about primary engines. It might make the control difficult to use.

When I use my kicker lowered like that, the tiller handle is at a steep upward angle. It's easy enough to use at the speeds it pushes my boat (about 5 mph wot, but usually trolling speed), with a 30 hp pushing a smaller boat on plane, I would suspect it might get dicey steering it safely.

 

[bagnallt]

Re: 15inch johnson. 30 hp.. can i uses a jack plate

yes it is the primary motor. I see your point it has the older style steering arm which connects to the teleflex steering via a plate which mounts on the motor mounting brackets. or fits on the transom with an extending arm to the motor.

 

[JB]

Re: 15inch johnson. 30 hp.. can i uses a jack plate

Short shaft outboards in that power range are in such demand that you should be able to swap for a long shaft engine in a nanosecond.

Failing that you should be able to swap the right parts for long shaft parts and a few bux.

Exactly what 30HP engine do you have?

 

[bagnallt]

Re: 15inch johnson. 30 hp.. can i uses a jack plate

hi there its a 1987 Johnson J30ECUB ... I wasnt sure if there was an extention kit for the leg. That would b the best Idea

 

[bagnallt]

Re: 15inch johnson. 30 hp.. can i uses a jack plate

I am really confused here.. I put this motor on the boat to acurately measure the didtance from the Anticavition plate to the bottom of the hull. Its 2 and a half inches higher than the bottom tof the hull. I put a long shaft on there.. ( its too powerfull for the boat its 50hp) and it sits perfect. I am confused as I assumed it would be 4-5 inches too short. I know I still need the plate in line with the bottom of the hull. But know need to drop the motor 2 1/2 inches.. crazy and confused!! BTW Measuring the transom.... I am right to take the perpendicular measurement and not the actual transome as it has an angle. to it..

 

[Lion hunter]

Re: 15inch johnson. 30 hp.. can i uses a jack plate

It is 4-5 " to short the cavitation plate should be 1-2" below the hull. If that motor is all you have I would run it. If you are talking about a kicker type jack plate I don't think I would put that big of motor on it. If you mean a cmc type lift then I think you would be allright.