Installing lanyard kill switch on 1971 Merc 7.5 HP with thunderbolt phase maker ignition

[FbnLny]

Hello,
unfortunately I didn't find any information about this, only for the older Phelon ignitions.
As the stator provides around 400V to the coils which passes through the points and kill switch to ground to fire, I am unsure if I can use a regular aftermarket lanyard type kill switch, as these are usually designed for 12/24V to replace the kill switch.

It is known that stopping the engine with the regular kill switch can damage the stator (if run on earmuffs), as it just cuts the stators ground connection, so I thought about using the switch to short the stator voltage directly to ground (or via Transistor if the Voltage is too high.) to stop the engine. Would this damage the stator?

What are your thoughts on this?

Thank you and best regards
Fabian

 

[alldodge]

With a 2 stoke OB the key switch and kill switch does the same thing, it grounds the magneto. To start the motor the key removes the ground

 

[QBhoy]

Yeah. Will work. Just put it across the existing stop switch circuit

 

[Faztbullet]

Get the kill tether with the 4 poles ...2 that are NO and 2 that are NC. Just splice it inline on the salmon wire before OEM kill button, attach to the NC terminals on new kill tether. This will break the ground from stator.

 

[FbnLny]

Alright, thank you for your replies!

 

[QBhoy]

As above…but historically I’ve always wondered about fitting one to some of my old 2 strokes and never did. Until recently a pal got an old DT16 Suzuki and put it on a 3 metre rib. He insisted on having one fitted just because he had to make a mile long crossing over sometimes rough water to get to his bigger boat’s mooring. Asked me to fit one for him. Was amazed at how simple it was. All I had to do was bridge it across the existing stop switch wiring. Obviously it’s in a normally closed circuit switch position, so when the lanyard is pulled it simply breaks the circuit to kill the ignition. Surprisingly simple. In fact the most complicated thing about the whole installation was where to put the assembly and switch, in terms of not having to ruin the loom of the lovely 40 year old engine or its casing