1973 85hp Johnson ignition problem

[sullivanm]

I was given this boat about 2 months ago. I am trying to get it lake ready. I know it has run in the past becuase I have used it. I put in a new deepcycle trolling, and cranking battery (875 cranking amps). After doing so, the motor cranked over 1 time so I left it. I was tracing wires to know what went from the front of the boat to the back. I then went to see if it would crank over again and it won't. The battery has a full charge. I have power going from the solenoid to the starter but nothing from the ignition switch to the solenoid. Does anyone have any suggestions? I have tried taking the shifter apart to check the wiring to know what goes to the motor but I can't get the top part of the shifter seperated to check the ignition switch. Any help would be great.

 

[Bifflefan]

Re: 1973 85hp Johnson ignition problem

If you have power to the starter, can you jump the starter and it will crank?
I dont know how to get your control box apart and you didnt say what kind it is.
Anyway, the ignition switch and neutral safety switchs are the next items to check. You can by pass the neutral switch to test it and just ohm the ign switch to see if its good.

 

[sullivanm]

Re: 1973 85hp Johnson ignition problem

yes, I can jump it and the engine will crank, but it won't start. The shifter is a Johnson Powershift II with the choke and ignition on the front side of the shifter. The ignition is on top of the choke. The choke works fine but the ignition doesn't seem to be operating correctly. I know that when the key is in the on position and I jump across the solenoid the motor should still start unless Iam not getting fire to the cylinders from the spark plugs. Haven't checked that yet. At any rate, my ignition is not cranking the motoer over unless I am jumping off of the solenoid.

 

[HighTrim]

Re: 1973 85hp Johnson ignition problem

Check the 20 amp fuse at the starter and also ensure that the wiring from the keyswitch through the large red plug to the engine is not cut.

 

[sullivanm]

Re: 1973 85hp Johnson ignition problem

Thanks for the replies all! I know the fuse is good, already checked it. My problem now is the wiring going to and from the ignition switch. Does anyone know where I could find a diagram for the ignition wirirng so I don't mess anything up. I guess the next thing I could do is check that I have fire going to all of the spark plugs and see if that is why it won't start. I have dealt with a situation like this in the past on a diesel truck and I wired a push button start going to the solenoid, as long as the key is hot going to the solenoid it should engauge the starter right? I'm still not convinced that something in the ignition isn't returning the hot fom the ignition wiring back to the solenoid. So any help on this is still appreciated.

 

[juanjuice]

Re: 1973 85hp Johnson ignition problem

you'll have to get a shop book climer has good wire routings if i knew how to put pic on here i would do it

 

[tashasdaddy]

Re: 1973 85hp Johnson ignition problem

use the search, i have posted the diagram several times.

 

[sullivanm]

Re: 1973 85hp Johnson ignition problem

Thanks