63 big twin wont shut off with key

[xtremefisher1]

so i have a 63 40hp big twin and when i adjust the idle to a proper idle the engine wont shut off with the key.. but if i bring it down to the lowest possible idle then put the throttle into the lowest possition is the only way it will shut down...

i have rewired the whole motor with an omc manual.. any ideas would be great and help....

 

[F_R]

Re: 63 big twin wont shut off with key

You have two black wires at the key switch---or at least the originals were black, on the two "M" terminals. Use a piece of wire, touch one end to each of the black wires. That should stop the engine. If it does, but the key doesn't, you have a bad switch. If jumping it does not stop the motor, you have a problem with your wiring job.

 

[xtremefisher1]

Re: 63 big twin wont shut off with key

if the key switch is bad will it still start the motor? and i will check the 2 black wires out once i get back to the boat.. also you can start it in gear now i figure that its the neutral safety switch issue .. will the safety switch have any effect on the ignition..

 

[lindy46]

Re: 63 big twin wont shut off with key

Keyswitch may still start the motor ok, but may not be shorting the two "M" terminals to kill the engine. Is your neutral safety switch working? I've seen motors where the switch died and the owner just bypassed the switch, allowing the motor to start in gear.

 

[xtremefisher1]

Re: 63 big twin wont shut off with key

i havent bypassed the switch its still in there. i did change it with another one but maybe that switch is bad or not set correct. i will change that also back to the origional one i had in there and if it still does it i will change it with another one i have kicking around..

 

[F_R]

Re: 63 big twin wont shut off with key

The safety switch only affects starting and the vacuum cut-out switch. It has absolutely nothing to do with shutting it down.