No spark at any cylinder

B

bankfishing

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Jul 21, 2010
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I have a 1984 Mercury Black Max V-6 outboard. CD Ignition type III. It cranks fine, but I don't have spark at any cylinder. I've checked the stator, trigger assembly, went ahead and changed all the spark plugs, by-passed the mercury switch - still nothing. Battery is fully charged, kill switch is in run...what am I missing?
 
C

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: No spark at any cylinder

Two common problems can cause a 'no spark' on all cyl's at once.

Grounded 'kill' wire. Test this by un-plugging the black wire with the thin yellow trace line from between both ignition modules and the motor wiring harness.

Slow cranking speeed. Minimum cranking speed is 300 RPM. Poor connection(s), dirty brushes, etc., can appear to be cranking O.K. yet not be near quick enough for the stator to generate sufficient voltage to fire the ignition.

This is where the DVA Meter is necessary.
 
B

bankfishing

Recruit
Joined
Jul 21, 2010
Messages
3
Re: No spark at any cylinder

Thanks for the help. Found the problem was the kill switch that I tested multiple times with the wrong wires. Probably still build the DVA as I'm sure it will come in handy.
 
B

bankfishing

Recruit
Joined
Jul 21, 2010
Messages
3
Re: No spark at any cylinder

Thanks CharlieB...my wiring diagram just said black/yellow. Didn't realize there was a black with thin yellow and yellow with thin black stripe. It was the switch.
 
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