'76 Johnson 9.9 converted to 15hp carb...

Finally got the boat out and took it for some test runs...

Here is the set up of the boat...

Back-Motor (76 Johnson 9.9)
1 Deep Cycle Battery
1 Starting Battery
6 Gallon Gas Tank (about 2/3's full)
Me (225lbs)

Front-36lb Thrust Minn Kota Trolling Motor
Piece of plywood (roughly 3'Wx4'L--3/4" thick)
MY Buddy (230lbs)

Middle-Fishing gear (30lbs worth maybe)


Motor is set all the way down (missing the pin).

With both of us in there and fully loaded we top out at 12mph and don't get on plane.

When he got out and was just me I topped out at 20mph and had no problems getting on plane.


I really didn't think the both of us in there would make that much of a diff. Could adjusting the motor help? Maybe a new prop? I took the starting battery out when we got home, I don't think I'm going to use it and that sucker weighed about 75lbs. So maybe that would help. Any other suggestions that may help me out?

Maybe if you had a tilt pin you might get better speed with all that weight by putting it on second hole from the bottom.That would keep the front end up which might help.I know I change my pin for different weights.

You may want to think about using a U1 size battery like riding lawn mowers use, should be enough cranking amps for your motor and they weigh around 20lbs. I'm using batteries that size that were used in motorized wheelchairs. They are AGM and are able to start my 15 Suzuki even after running my trolling motor fishing for half an hour or so. Best part is they were considered used and I only paid $15 each.

Well I don't even really have to have the starting battery. The motor is not electric start. I just had it in there for running the nav lights/fog lights/12v plugins. So all that's in there now is the deep cycle.

I will look into getting a tilt pin and trying that out. Know where I could pick one up?

Ok, still trying to find a tilt pin that does not cost $50. Anyways I got to messin with the motor and noticed this little lever type thing that is spring loaded.

Which way should it be? Picture 1 or Picture 2?

That is a shallow water drive bracket, which rests on the tilt pin when you slide the tilt lever to tilt and only partially raise the engine. When you move the lever back to Run and raise the engine slightly then lower it the bracket should fold away and not contact the pin allowing the engine to gain the fully tucked under position.