No Spark 2003 15 HP Mercury 4 Stroke

[111torrance111]

I have a 2003 Mercury 15 HP 4 Stroke that has no spark, need help/advice.

Problem: Boat was donated and don't have any history, started working on motor and determined the components under the flywheel needed replacement.

Replaced the Coils/Lighting & position sensor, also replaced the ignition module and rectifier, still have no spark to the plugs.


The boat is set up with a side mount throttle with a kill switch, the switch is shorted to ground in either position.

How do I determine if the problem is within the motor or the ignition system?

Please help.

Serial # ot723829
Model # 15 HP EL 4 stroke

Jerry

 

[Star]

You have gone about this the hard way. A factory manual gives you a way to check the resistance of all ignition components. The motor may have a safety kill circuit. There is also a run switch on that motor that will kill your spark. My 05 developed a coil problem in 2013, but it was only one side of the coil output. I did not see a coil replacement in your list. The resistance readings aren't always bad but they can show a change. My coil read fine but I would loose a cylinder under load.

 

[Star]

That switch shoule be open to run!!!