1990 force 50hp spark issue

[hbagley]

Ok well this is my first post on here so please bear with me. I have a 1990 force 50hp model 507X90D. I had the boat out over the weekend and noticed I was way under-powered. My first thought was a fuel issue as the motor sounded fine and was running smoothly. I had good fuel and made sure the tank vent was open. I also removed my in line fuel filter just in case. The issue still persisted. I the thought to check spark. I have the blue ignition coils (2) and the blue CDI (1). I had great spark on one and very weak if any spark on the other pack. Tried new plugs and no improvements. I then swapped the packs. The pack with no spark before now has spark and the one with spark before doesnt spark anymore. The thing I am wondering is do I have a bad pack or a bad cdi ? I was initially thinking pack, but now am not so sure. Could one side of the CDI be working fine and the other is bad ? The CDI and one pack was just replaced about a year ago. Any thoughts or input would be greatly appreciated before I go putting more money in to this. I have a Clymer manual but its not very helpful in this situation.

 

[pnwboat]

When you say you swapped the packs, are you saying you swapped the coils. If so, then it seems from what you described that the problem followed the coil. It would appear that you have a bad coil. Having said that, take a close look at the connectors on the wires for the CD Module and trigger where they are attached to the terminal strip. Very common for wires to strands of wire to break right at the eye connector causing all kinds of intermittent odd ignition issues.

Yes it is possible for one side of the CD module to go bad causing ignition spark problems on one of the two coils that it supplies voltage to.

 

[hbagley]

As far as swapping packs. My cdi has two female plugs on it. I simply switched out which igntion pack was plugged into what wire. For example pack 1 worked when plugged into wire A on the CDI. Pack 2 did not work when connected to wire B on the CDI. I took the wire from pack 1 and hooked it into wire B and wire from pack 2 into wire A. Now pack 2 works and pack one doesn't. I will check connections as soon as I post this. Hope this clarifies things up a bit.

 

[hbagley]

Just checked connections. all wire are intact and all connections are tight. I just tried again with the packs. I have consistant spark on one pack and not the other. It doesn't seem to make a difference what connector on the cdi the pack is hooked up to one will always have spark, and one won't. So are you thinking bad pack or bad cdi? Just to make sure we're on the same page I'm referring to the CDI as the larger of the three blue boxes with about twelve wires on it and the ignition packs as the ones with just a ground, spark plug wire and white wire with a red and orange stripe. Also tried with just one pack hooked up. When I do that the pack has a weaker spark. As long as both packs are hooked up the spark is stronger. Is that normal or do I possibly have another issue going on ?

 

[Frank Acampora]

Probably a bad CD module. However, check the resistance on both triggers If a wire is broken, it will show infinite ohms. Wiggle the trigger wire a bit while testing if there is sporadic spark on one cylinder

 

[hbagley]

Got a used pack today. hooked it up and now have spark on both cylinders. thanks for the input