1977 120hp omc sterndrive starter circuit problems

[1949Buzz]

OMC starting circuit problem

I have a 1977, 120 hp OMC Sterndrive that hasn't been in the water for 4 years. My grandson has been putting pressure on me to take him fishing. I have replaced the fuel, fuel pump, assist starter solenoid, and ignition switch. Starter motor continues to operate after releasing key to run position, but will stop when wire to assist solenoid is removed from switch. Motor continues to run fine. Would appreciate any advise on why the starter continues to run until wire to assist solenoid is removed from switch.
Thank you,
1949Buzz

 

[Scott Danforth]

welcome aboard

your switch is shot

 

[alldodge]

replaced ..... and ignition switch

Check the voltage on the start post of the ignition switch to see if 12V remains when the key is released.
If it remins then your new switch is bad

If voltage is not present, then check your wiring at the assist solenoid

 

[1949Buzz]

1977 OMC starting circuit problem.

I replaced my starter assist solenoid and ignition switch. Engine will now start, but starter does not stop when key is released to run. If I disconnect wire that goes from the ignition switch to the shift control, the starter motor will stop and the engine will continue to run. Would appreciate any advise anyone might have.
Thank you!

 

[alldodge]

Need to look at your other thread started
https://forums.iboats.com/forum/boa...-motors/10807609-omc-starting-circuit-problem

 

[1949Buzz]

I have recently replaced my assist solenoid and ignition switch. Engine will now start, but starter motor does not stop once engine starts and key is released to the run position. If I disconnect the wire between the switch starter terminal and the shift control lever, the starter will stop and the engine continues to run., I would appreciate any advise that anyone would have.

 

[1949Buzz]

Thanks for advise. I am new to iboats and haven't figured out how to navigate it completely. I appreciate help and will head out and check voltage at start terminal. Doesn't make sense to me that starter will stop when wire from switch start terminal to shift lever (and on to assist solenoid) is disconnected from switch. Maybe I did get a bad new switch, however the same thing was happening with the old switch that I just replaced which makes me a little suspicious. Thanks again.

 

[southkogs]

Moved this into the OMC forum. Welcome aboard 1949Buzz.

 

[1949Buzz]

This problem seems to be getting crazier and crazier (and so am I) While testing, I have connected the wire from the shift control to the ignition switch with a remote starter switch so I can quickly disconnect once the engine starts. The starter would continue to run after the engine starts if this wire is not disconnected at switch. A very strange thing I noticed is that the starter terminal on the switch registers 20 Volts with engine running in run position, and wire to solenoid on starter connected, and wire to assist solenoid disconnected. Checked with analog and digital meters because I couldn't believe what I was reading. I believe all connections are in the right place. Might be time to try to find someone to look at. Most marinas in my area (Oregon City, OR) do not want to look at a 42 year old boat And all the while my grandson keeps asking "grandpa, How is the boat coming?". Afraid at this rate, we may miss the fish run. Again, I appreciate this forum and any advise someone might have.

 

[kenny nunez]

Is your stern drive electric shift? If so then your problem could be the shift switch in the control box. They can break internally and the current that feeds the drive is back feeding the neutral safety circuit.