1978 merc still has no spark

no spark

Cadet
Joined
Aug 5, 2005
Messages
20
I have a 1978 mercury 70hp merc ( serial #4826566). Just installed new wiring harness,switch bow,stado,trigger,coils & rectifier. Engine cranks but still get no spark. Can someone please help or have any ideas what else it could be.
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: 1978 merc still has no spark

Welcome to iboats. :) <br /><br />You might have a mercury switch gone bad. It's mounted at an angle and is intended to kill the motor if the tilt angle gets too high. It has 2 brown leads coming out of it. Disconnect the one that goes to ground and see what happens.
 

no spark

Cadet
Joined
Aug 5, 2005
Messages
20
Re: 1978 merc still has no spark

I replaced the switch box before checking the stador and trigger. Is it possible the switch box could have blown again.
 

no spark

Cadet
Joined
Aug 5, 2005
Messages
20
Re: 1978 merc still has no spark

Checked the mercury switch and it's OK. Any other ideas
 

andy6374

Lieutenant Commander
Joined
Aug 4, 2005
Messages
1,617
Re: 1978 merc still has no spark

Wiring harnesses can always give you the can of worms, even new ones. Disconnect the harness and jump the starting solenoid with something (screwdriver or large gauge wire) and see if you get spark
 
Top