71 Johnson 60 hp runs in water but won't start there.

[BigDukeSix]

I have a 1971 Johnson 60 hp hydro electric shift. Motor has been pretty dependable over the last year. Started acting up recently. I rebuilt the carbs. Checked compression (all at 120psi), and put in new plugs. My current situation is this, it will start and run perfect on muffs. It will not start when put in the water. The spark is there but weak when the boat is in the water. I can tilt it up out of the water and wait a minute or two and it fires right up. I drop it down and off I go. If I shut it off I have to raise it up out of the water and wait a minute and it will start right up. My reverse doesn't work (wiring and switch checks out so I am thinking a bad solenoid). I am wondering if that bad solenoid is grounding against the case causing a drain from the amperage going to the ignition system during cranking. Any other ideas? Thanks

 

[kodibass]

Re: 71 Johnson 60 hp runs in water but won't start there.

The only thing I could suggest is the process of elimination, lower motor in the water and try to start with a direct jump to the starter motor and see if it starts, then move to the starter solenoid, see if it starts etc., one other thing could a wire be getting pinched in the lower position? one last thing use a multimeter and check voltage at as many points as you can while starting in both up and lowered positions this might give you a lead to whats happening. good luck.

 

[BigDukeSix]

Re: 71 Johnson 60 hp runs in water but won't start there.

I should have clarified, it cranks over just fine up or down. Just won't start when lowered in the water. It will crank and fire in the down position out of the water just fine. All wires look good with no cracks or breaks. All connections and grounds cleaned and tightened. Weak spark seems to be the problem when it is lowered in the water. Battery maintains 10.8 volts during cranking which is more than the minimum 9.5 required for the ignition system. Other than the back pressure of the water on the exhaust, I can't put my finger on what difference it being in the water would make.

 

[sutor623]

Re: 71 Johnson 60 hp runs in water but won't start there.

Yes I think you are right. It sounds like you may have a short somewhere. I found a short in my motor by firing her up at night so I could see where the sparks were coming from......