Kill Switch Question

[jayhanig]

Yesterday I was at the boat ramp when a 21' Sea Pro equipped with an Evinrude OB was towed in. The owner told me he'd been cruising down the Intracoastal Waterway when the engine quit and then it refused to start. I asked if "refused to start" meant it cranked but didn't catch or if nothing happened when he turned the key. He said nothing happened when he turned the key. When he tried it again, sure enough there was nothing: no clicking noise; nothing at all.

I was curious if the solenoid was the culprit and so we found a screwdriver and I held it across the terminals of the solenoid with the key turned to the "on" position. The starter engaged the flywheel and spun it energetically but the engine never even tried to catch. Hmmmm.

The next thing was to gain access to the back of the ignition lock and suddenly the engine started just with the key like it normally should. The owner insisted he hadn't done anything but who knows?

My question has to do with its subsequent behavior: pulling the kill plug caused the engine to stop immediately, as I would expect it to. What I don't understand is the engine could then be started with the key even though the kill plug was still unattached. Is that normal?

I really think his problem is all in a hinky kill switch but I'm no authority when it comes to such things. What do you think?

 

[Home Cookin']

Re: Kill Switch Question

I have heard that some motors will restart with the key after the kill switch has been yanked; this is so the crew can go get the skipper who was thrown overboard with the lanyard attached. But I tested my Yamaha and it doesn't. I may test my Johnson this weekend.

the kill switch cuts the power to the spark plugs--I don't down how far upstream (power pack?)

This suggests a bad (corroded) connection in the ignition area: "gain access to the back of the ignition lock and suddenly the engine started just with the key like it normally should."

 

[jayhanig]

Re: Kill Switch Question

Thanks for the quick response. There is nothing more anxiety producing than a solution that presents itself for no apparent reason. If I owned that boat, the next time it happened I'd likely be out of sight of land. That's the kind of luck I've historically had. In any case, with no real understanding of why the boat healed itself the first time, there's no guarantee it would work again the next time.

That being said, I fully accept the bad connection explanation. Now all he has to do is find it. Cursory visual inspection of the back of the switch didn't reveal any obvious corrosion. And judging by the condition of the boat and its engine, I'd say the owner was pretty good about keeping his boat up. He apparently doesn't just let things go.

In any case, I think I talked the owner into joining Sea Tow.

 

[Home Cookin']

Re: Kill Switch Question

intermittent electrical problems and salt water boating have driven many a man to play golf instead.

 

[Quad82]

Re: Kill Switch Question

Most kill switches on older motors are NO (normaly open) and ground out the switch box (like on my old Merc), the coil or CDI when the teather is pulled. The newer motors and some of the older ones can be NO or NC (normaly closed) and either ground out or open a circut. If his was a NO kill, corosion at the ground wire end or the electric componet end or a loose connection wouldn't make a difference because it would still be an open circut. Unless the switch itself was in trouble (shorted) from corosion or internaly broken. A shorted electronic side wire of the switch that was pinched or rubbed bare aganst a metal object would act like the switch was activacted too. But if it were a NC loop, a loose or corroded connection would indeed cause it to not start. Find both ends of the kill switch and unplug them. Using a ohm meter or a test probe, connect to both the far ends of the switch wires. With the teather connected, the meter will show resistence or lite the probe if it's a NC switch and nothing if its a NO switch. Wiggle the wires to see if you have an issue with them. To test for a NO switch pull the teather and it should show resistenance or lite the probe. Wiggle the wires to see if there is an issue. Granted, a bad switch could make a NO switch test as a NC switch and a NC switch show as a NO switch. BUT pulling the teather to trip the switch or installing the teather to arm the switch will read the same. Meaning both test will show the switch open or they will show the switch to be shorted.

 

[dingbat]

Re: Kill Switch Question

I have heard that some motors will restart with the key after the kill switch has been yanked; this is so the crew can go get the skipper who was thrown overboard with the lanyard attached. But I tested my Yamaha and it doesn't. I may test my Johnson this weekend.

No problem restarting an Evinrude/ Johnson. Noted as a saftey feature in the operator's manual. I 've never used the "clip"

 

[zenwriter]

Re: Kill Switch Question

No problem restarting an Evinrude/ Johnson. Noted as a saftey feature in the operator's manual. I 've never used the "clip"

Same here: I don't use the kill lanyard on my 90HP year 2000 Johnson. If I use it shuts the engine down when pulled off, but then starts right up again without using the lanyard.

 

[glenn property of pam]

Re: Kill Switch Question

lanyard kills the ignition not the starter, netrual safety switch kills the starter but not the ignition. Loose wire with corrosion thats pulled around on the back of the ignition switch (kinda cleans the connection) seems to fix all the problems. Hope you are around the next time it happens