Ignition problem. Please help

[Dubbz75]

Hello everyone. I'm new here and hope you wonderful people can lend a hand. I have a 1989 Mercury 200 efI that I am having trouble with. I have intermittent spark on all cylinders. When I put a timing light on the plug wires I don't get a steady flash. There are blackouts randomly. I have changed the stator, trigger, switchboxes and even the flywheel. I have swapped a single coil with a known good one as well. I am at my wits end with this motor. Hope someone can help. Thanks in advance

 

[gm280]

:welcome: Dubbz75 to iboats. Always great to have a new member join...

I read your thread and there are a few things you can check. First, what type plugs are you using and are they gaped correctly? The fact that your timing light is showing random spark issues with all cylinders means you have something that isn't firing on every turn. And if the plugs are gaped correctly and the spark wires are good, then you have whatever triggers the spark. Not having your actual model number and serial number, I can't look up your ignition setup. I would start with checking all electrical connections. Even if they look good, remove them and clean to the bright shiny metal and reconnect. Could be a ground wire or connection not making properly. You will need to post your model number and serial number for more ideas. JMHO

 

[DavidMoore]

+1.

Remember someone on this forum having a similar issue, turned out to be a wire with damaged insulation and was shorting out to ground. So there's something else to check.
Good luck.

 

[Dukedog]

if you have changed those items tha only thing left will be tha wiring itself or a bad timin' light....those parts are all that produce/control tha 'lectrics..is it a 16amp or 40amp system (that year had both).... is tha drop random/moves around are always on tha same cylinder/cylinders?.. does tha motor actually miss when this happen or do ya just see it with tha light?

 

[Faztbullet]

Disconnect the rectifier....