Ignition switch - How do I turn it off?

[Vintage Iron]

I'm cleaning up the magneto assembly on my 1961 Sea King 5hp, and there's nothing installed to open the circuit between the points and ground. On the cowl I don't see any hole for a kill switch or ignition switch, and on the throttle grip there's no "OFF". So how do I make it stop?

 

[brim_buster]

Is it a twist grip control ? Wait for FR to reply, hes the expert on those motors....

 

[Vintage Iron]

Yup, twist grip with a gear selector (F-N-R) on the other side. Pretty basic, but I'm clueless.

 

[Grub54891]

There might be a button right in the middle of the tiller handle.Check there. The rubber gets hard from age, some have to be pressed fairly hard.

 

[gm280]

IS it set up so that when you twist the throttle to the lowest position it stops the engine? :noidea:

 

[Vintage Iron]

Grub - No luck on locating a switch anywhere on the tiller. No wiring inside the tiller or attached to it, and when I pull the rubber off, all I see is a friction washer and spring.

GM - That's what I was wondering at first. But the throttle plate has two holes drilled through it and a small cutout on the bottom edge. To me, it looks like there'll always be enough air entering to allow it to idle.

I gotta tell ya, I'm really stumped. I mean, pulling the fuel line off every time I want to stop the motor seems kinda lame. Besides, I've read elsewhere on this website that some folks have a lanyard attached to an ignition kill device, so that if they ever fall off/out of the boat, the engine shuts off. Well, if I ever bail from this puppy, it's gonna be in Oklahoma before it quits! hwell:

I still have to go through the lower end/prop drive stuff, so it'll be several more weeks before I have it running. Fortunately, if I need to design a circuit to handle this, there's plenty of time to do it. Thank you both for your ideas and for taking the time to respond. If anything else occurs to you, please let me know.

Dave

 

[RCO]

No kill switch on that motor, or most all motors of that era. The throttle will retard the timing to the point where the engine will not run. The carb only opens at higher speeds, engine speed below about half throttle is controlled by the timing advance. If you really feel it's necessary you can add a lanyard switch- one wire to each set of points.

 

[Vintage Iron]

RCO -

Thanks for the info! I never gave a thought to timing being used to stop the motor. So basically, I'll twist the grip "full off" and the engine quits. That is very neat. And simple.

Dave

 

[gm280]

VI, usually tiler setups on some of those engine use the throttle twist to stop the engine. However, you still could install a kill switch so if you do fall out, it instantly stops the engine so it doesn't circle around and run over you. Just an idea.

 

[Vintage Iron]

Yup, that's still a thought in the back of my mind. Being able to kill the ignition would make troubleshooting a lot simpler. And less exciting.

 

[Vintage Iron]

gm280 -

While searching through the archives for info on capacitor testing, I stumbled across a kill switch schematic contributed by you last month. This is exactly what would work on my setup. GREAT IDEA!!

http://forums.iboats.com/forum/engi...4081-1976-johnson-seahorse-now-no-spark/page3