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95 SPX Electrical Issues

When starting, what should the voltage going into the coil pack be? is it supposed to fluctuate? is it normally supposed to be 12Volts consistently going into the Coil Pack? If its not what it is supposed to be? does that mean a bad MPEM? because that's where the coil pack connections come from. would the rectifier have anything to do with it? Putting my multimeter in measuring the voltage going to the coil pack while starting the voltage jumps all over for me. It never really gets to 12 volts jumping between 4-7 volts. Is this correct or do I have a bad MPEM? I cannot find anything about the electrical system for a 95 SPX Rotax 657X anywhere.
Anything Helps,
Corbin.
 
There is a shop manual for your ski at seadoomanuals.net. It has an electrical section that descibes the ignition coil and generating coil as well as schematics. I took a quick look and I think the generating coil is generating current pulses that drives the ignition coil that the manual says has an integrated CDI that would generate the high voltage for the plugs. I think the generating coil is also just an input to the MPEM.
Are you getting spark? If not the manual should have tests for the coils, stator and plug wires (usually resistance measurements).
 
These are CDI ignitions so the coils don’t work like older car coils as they don’t get battery voltage. They a more like a transformer boosting the voltage when the capacitors discharge.
You aren’t going to get 12v to them.
 
There is a shop manual for your ski at seadoomanuals.net. It has an electrical section that describes the ignition coil and generating coil as well as schematics. I took a quick look and I think the generating coil is generating current pulses that drives the ignition coil that the manual says has an integrated CDI that would generate the high voltage for the plugs. I think the generating coil is also just an input to the MPEM.
Are you getting spark? If not the manual should have tests for the coils, stator and plug wires (usually resistance measurements).
Getting Spark but it doesn't start. I've changed out everything on the ski besides some of the electrical components so i was thinking maybe the reason it wasn't starting was because of weak spark or incorrect spark timing. The coil pack is one thing I replaced. The MPEM and Stator is have not.
 
Do you know if it is getting gas. Try a little premix down each carb and see if it fires. Do you have the grey fuel lines? When was the last time the carbs were rebuilt?
 
Fuel lines have been replaced, I tried gas down the carbs and starter fluid the other time and still didn’t even sound like it was firing. Carbs haven’t been rebuilt but only run premium gas through them also checked the fuel filters in the carbs and they are clean.
 
Did it ever run? If so then probably not the timing. Run all the resistance tests on the ignition coil, generating coil, stator and plug wires. Make sure your battery is charged and load tested. When was the last time the plugs were replaced? I don't think the rectifier would affect starting but you could disconnect the red wire coming from it to take it out of the picture.
 
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