Help my old gal won't start

[crossroads123]

Hello to all, I have been a member for a long time but, haven't been on line in several years. I finally got my old gal, (boat not wife) out of the barn to give it to my grandson. She has been barned for several years time for her to be loved and used by someone much younger.
My problem is she cranks, but has no spark she is a 1993 Mercury 40 hp, 2 stroke, 4 cyl. There is no spark on any of the plugs batteries are fully charged and it cranks fine. I had my repair manual loaded on another computer that took a dive. I appreciate any help you may give and thank you in advance.

 

[Chris1956]

Those motors ground the switchbox to kill the spark. Disconnect the black/yellow at the switchbox and see if speak returns. If so, suspect the wiring is grounded somewhere or the ign switch is bad.

If the motor had a kill lanyard, check that as well. I would expect it has a switch on the MerControl for that purpose.

 

[racerone]

Load test the battery.----Replace water pump impeller when you get it going.

 

[crossroads123]

Hey guys thanks for the replies I have already tested the kill switch no luck and still no spark. I called local repair shop today said he was a month and half behind. I am still searching for troubleshooting help. Thanks again.

 

[Chris1956]

Did you "Those motors ground the switchbox to kill the spark. Disconnect the black/yellow at the switchbox and see if speak returns. If so, suspect the wiring is grounded somewhere or the ign switch is bad."