1987 mariner 90 hp 3 cyl. no spark

F

fishallday

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Jun 12, 2009
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I have a 90 hp 3 cyl. 1987 outboard mariner with no spark on any cylinder at all. i replaced flywheel, trigger, stator, and switchbox all brand new. i have 30 volts coming from the stator going into the switchbox on the red and blue wires. i have 9 volts coming from the trigger going through the three wires to the switchbox. tilt switch isn't causing it. ohm all three coils their ok, but have no voltage leaving the switchbox going to the coils. any help would be good to get. if anyone has a wireing diagram for this particular engine please let me know. i have the manual for this but is isn't that great. i have no more parts to replace so i hope someone can help me.
 
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CharlieB

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Apr 10, 2007
Messages
5,617
Re: 1987 mariner 90 hp 3 cyl. no spark

Look on the switchbox for a black wire with a yellow stripe on it.

Disconnect this wire and retest for spark. This is a 'Ground-to-kill' wire which shorts out the ignition. Any ground on this wire, at the safety lanyard, ignition switch, or a stray screw that punctured the wiring harness and the motor dies.

Oh, and this ignition has a minimum cranking speed of 300 RPM, slow cranking from a weak starter or poor connections and no spark.
 
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F

fishallday

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Jun 12, 2009
Messages
2
Re: 1987 mariner 90 hp 3 cyl. no spark

thank for responding. i have tryied that all ready. still nothing i have bought an aftermarket stator and switch box wondering if that could be the problem. or could the wrong flywheel cause no spark? this is a project motor i got it with no flywheel . it has a brand new starter and battery
next thing im going to try is going to check part no. on the parts i have .
 
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