1964 Lark 6 Safety Switch question.

lindy46

lindy46

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Nov 27, 2008
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Got the wiring all figured out on the Lark, and have a question on the Safety Switch. From the looks of the wiring, it appears the safety switch functions in the same way as the old mercury switch? If the throttle advances too far, it grounds the solenoid preventing the starter from turning. Is that correct or does the safety switch prevent spark to the plugs? The reason I ask, when I first put power to the engine, I momentarily had a strong spark to the top plug (I was checking compression at the time). When I switched to check compression on the bottom cylinder, I had no spark to the bottom plug. I then rechecked spark on both plugs and had none. I haven't been under the flywheel yet, so I don't know the condition of the coils. The starter turns over the motor at any throttle setting.
 
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F_R

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Re: 1964 Lark 6 Safety Switch question.

lindy46 said:
Got the wiring all figured out on the Lark, and have a question on the Safety Switch. From the looks of the wiring, it appears the safety switch functions in the same way as the old mercury switch? If the throttle advances too far, it grounds the solenoid preventing the starter from turning. Is that correct or does the safety switch prevent spark to the plugs? The reason I ask, when I first put power to the engine, I momentarily had a strong spark to the top plug (I was checking compression at the time). When I switched to check compression on the bottom cylinder, I had no spark to the bottom plug. I then rechecked spark on both plugs and had none. I haven't been under the flywheel yet, so I don't know the condition of the coils. The starter turns over the motor at any throttle setting.
Click to expand...

The safety switch is the ground return for the starter solenoid coil. It is closed (grounded) at slow throttle setttings, allowing the starter to function. At high throttle settings, it is open (ungrounded) and the starter won't run. Somebody has dinked around with the wiring if the starter runs at any throttle setting.

It has nothing even remotely to do with the spark problem.
 
lindy46

lindy46

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Joined
Nov 27, 2008
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3,886
Re: 1964 Lark 6 Safety Switch question.

Took the safety switch off and the button was stuck in. Cleaned and lightly lubed it, and it now works fine. Tomorrow I'll pull the flywheel and see what's going on under there. I finally got good strong spark to the bottom cylinder, but nothing to the top. Gotta go purchase a 1-1/16" socket to get that flywheel nut off - didn't realize it was that big until I went to take it off.
 
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