1975 mercury 650 no spark

krs60

Petty Officer 2nd Class
Joined
Aug 30, 2009
Messages
131
Does anyone have a link to a troubleshooting guide for this motor?

I do not have spark. Parts replaced are complete distributor, coil, switch box, and the mercury switch. Maybe i'm missing something???
 

procraftguy

Petty Officer 2nd Class
Joined
Jul 7, 2013
Messages
137
Wiring issue check wire diagrams to get spark on that motor white is 12volt whithe key on red is 12 volt all the time
 

krs60

Petty Officer 2nd Class
Joined
Aug 30, 2009
Messages
131
Looks like my wiring problem might be an incorrect ignition switch.
The dealer gave me a switch with c-m-s-b-a-s on the back of it.
According to the manual i need a switch with a-b-d-e-f on the back of it.
I googled the switch and cannot find the correct one. Anyone have a link i could follow?
 

bunnybuster

Cadet
Joined
Jul 5, 2014
Messages
6
Hi,
I am having the same problem with my 1973 650 mercury engine.
Intermittent firing. I believe it could be the ignition switch. I would like to find a real electrical schematic for the wiring, other than the line diagram.
I have the same switch as yours a-b-d-e-f .
I need to find a new switch...and start there.
Any help?
 
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