Merc 1979 40hp won't shut off sometimes

[rich43]

I have a 79 Merc 40 hp with electric start. It sometimes (about 1 in 4) will not shut off when the key is turned off. Any suggestions?<br /><br />Thank You

 

[Fouled Plug]

Re: Merc 1979 40hp won't shut off sometimes

I would trace the wiring from the key back, checking for loose/corroded connections. Make sure your grounds are all clean and well secured.

 

[Mod2]

Re: Merc 1979 40hp won't shut off sometimes

Moving to Mercury/Mariner forum.

 

[rich43]

Re: Merc 1979 40hp won't shut off sometimes

I checked and could not find a broken or loose connection. It could be a broken wire in the cable. Is there a way to connect a "kill" switch using a separate wire?<br /><br />Thanks for the information.