Kill switch question

[iggyw1]

I just bought a used boat and motor. 35 H.P. Johnson, 1991 model, has no kill switch on it to connect a tether to in case I fall out of the boat, I want the motor to shut off. Is it easy to install a kill switch onto the ignition switch somehow?

 

[Scott Danforth]

Yes, get the universal kill switch and wire it.

 

[Nordin]

You should have a kill switch with a normally open function.
It should close the switch when pulling the lanyard.
Wire it parallel with the stop function at the key switch and to ground.
Black/yellow is the stop wire and you ground it out when killing the engine.

 

[Scott Danforth]

the universal has both the NOHC (Normally Open, Held Closed) contacts and the NCHO (Normally Closed, Held Open) contacts

the NOHC will have the purple wires for use on the powered ignitions. when you pull the lanyard, the switch reverts back to open, thus killing the ignition.

the NCHO will have the black (ground) and yellow (magneto or switch box) wires and close when the lanyard is removed, thus grounding the ignition and killing it.

 

[Nordin]

Scott I think you reversed the function of the NOHC and NCHO in the explanation of the function or do I think backwards?.
NOHC normally open when lanyard is in and closes when pulling the lanyard.
NCHO normally closed when lanyard is in and opens when pulling the lanyard.
Function should be as I described in my post above.
When pulling the lanyard the switch should close and ground out the ignition.

 

[Scott Danforth]

Scott I think you reversed the function of the NOHC and NCHO in the explanation of the function or do I think backwards?.
NOHC normally open when lanyard is in and closes when pulling the lanyard.
NCHO normally closed when lanyard is in and opens when pulling the lanyard.
Function should be as I described in my post above.
When pulling the lanyard the switch should close and ground out the ignition.

Remove the lanyard for the normal contacts.

The position the internal spring loaded contacts are at rest without the lanyard clip.

Add the lanyard to hold the switch in the non-normal position

My terminology is correct

On a NCHO kill switch for magneto ignitions, the normal position is closed/motor off. Adding the lanyard clip opens the contacts and holds them open for operation

 

[iggyw1]

Looks like a hole with a plastic plug knockout plug blocking this hole currently on the motor control where the key switch is along with the throttle and fast idle. I am assuming this hole with the "knockout" plug is where the kill switch should be mounted and it seems like it probably would fit inside the control box. Never had one of these apart myself. Are they spring loaded or anything special I should look out for when opening the control box up? I don't want things to go flying out on me and not knowing how to put it back together. Is it a job for a do it yourselfer or should i let the pros handle this one? I am sort of mechanically inclined to try it as long as it is not spring loaded or anything.

 

[saltchuckmatt]

Not spring loaded.....lots of parts but doable.