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1995 Mercury 90 HP no spark

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akig0711

New member
So from the beginning, I had a bad oil feed check valve and fixed that and rebuilt all carburetors. While running motor I was spraying combustion chamber cleaner into the carburetors and stalled the motor. I was pretty sure I flooded it but wanted to verify that all else was good so I did a spark check. I don't think I had a good ground and am pretty sure I fried something but i'm not sure what. I finally found some troubleshooting guides on the CDI website and tried to shoot the stator. I have the red stator and while shooting for resistance between green/white and white/green I was only getting about 30 ohms when it should be 500-700. I used a homemade DVA and was getting anywhere from 120 to 180 VAC when trying to turn the motor over. I started playing around with the wiring and disconnected the black/yellow wire on the switching box (saw somewhere that this might be the shut-off signal) and tried to start and the motor started. First time it's done this on at least a hundred tries. I shut it down and reconnected the black/yellow wire and it started again. I ran it for a few minutes and attempted to give it a little throttle and it died. I tried to start it again and no luck. I checked for spark with an inline spark plug tester and nothing on either cylinder. Checked the voltage out of the stator again and am only getting around 60 VAC now. Does anybody have any insight on what might be the issue? Is the black/yellow the shut-off and should it be open for the motor to start? Any help would be much appreciated.

Model #: 1-090412R
Serial #: 0G197967
 
that black/yellow wire goes to your kill switch...it is normally open and closes and grounds the power pack(sometimes referred to as a switch box) to kill the engine when the lanyard is pulled free...it should read open for the motor to start....another check you should do is to make sure there is no voltage on that wire when it is disconnected...any voltage will damage the switch box...this check is on the wire going back to the kill switch and should be zero voltage...it will be ground if the lanyard is pulled..
 
Papyson, thanks for the info, I know that the black/yellow is grounded out somewhere in the boat, not sure why the boat started after I hooked it back up, maybe an intermitent short. This will be the first thing I fix when I get a chance to work on it. Do you know if you can shoot the blue wire (the green/white and white/green go into a small sealed box and the blue wire comes out and goes to the switch box) with a DVA and get voltage and if so do you kow how much. If I can get voltage from the stator I can verify that the small box is not stopping the signal.
 
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