TOPIC: MERCURY - (200 H.P. (1988 ))

I have a MERCURY - (200 H.P. (1988 ))
Serial No: 0B242347 Model No: 1200412BD which is on a 19ft Kona.

It has run well but now it will not start. It turns over but there appears to be no spark. I think no spark because if I remove a plug and ground it and turn the ignition on and try to start it I see no spark on the plug.

So, the question is how to diagnose this and what could the causes be for this.

Thanks for any advice,

Ken

Hi Ken, I would check the simple stuff first. Check your kill switch, they have a habit of going bad. Pull all six plugs and check for spark, if 3 have spark and 3 dont its a switchbox. If none of them have spark then it is either kill switch or ignition switch. Check for 12V with the key in the on position. Check at the motor end, if you have 12V the switch is OK, if not then work backwards towards the switch, could be a rotted off wire.

I do not believe that the ignition system uses 12 volts from the battery to make spark.

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The ignition is run from the magneto under the flywheel.

Thanks Dave and Professor for the replies. When I was checking for connections/corrosion the terminal fell off of the starter solenoid! So I have one on order now and will have to wait for that to come in to continue.

Joe Poole also said check the kill switch and that the two switchboxes don't usually fail at the same time.

I don't actually see/know where the kill switch is on it. I have never used one, ie, I just have an ignition key.

Thanks,

Ken

The Professor is correct, the 200HP V6 uses ADI (Alternator-Driven Ignition) which doesn't require power from the battery to make sparks.

Here's a troubleshooting guide put out by CDI Electronics:

issuu.com/cdielectronics/docs/troubleshootingguide?mode=embed&layout=http%3A%2F%2Fskin.issuu.com%2Fv%2Fcolor%2Flayout.xml&backgroundColor=000000&showFlipBtn=true

The section for 6-cylinder Mercs with ADI starts on page 83.

You'll note that the first thing they have you do is disconnect the kill wires at the switch boxes & re-test for spark.

Some ignition components you can check with a meter, others require a DVA (Peak Voltage Reading Adapter) along with a meter. You can't check the voltage output of the ignition windings without one.

Here's an inexpensive tester:

www.usatoolwarehouse.com/usatoolwarehouse/ESI-640.html

I've also attached a pic of a D-I-Y adapter which you could build from Radio Shack parts for probably less than $5, see this iboats thread for the discussion:

forums.iboats.com/mercury-mariner-outboards/simple-easy-make-dva-adapter-standard-multimeter-374544.html

The Good News is, you can do resistance checks on the trigger assembly and the stator windings, and most of the time the resistance checks alone will tell you if there's a problem there. But the DVA is critical to doing in-depth testing, if you don't find it to be a simple or obvious problem.

HTH & G'luck with the troubleshooting.....ed

Indeed. With the above meter and adaptor that is a very simple ignition circuit to troubleshoot, you can breeze through the whole thing in less than half an hour with a little practice.