97 GTI Dead Electrical System Please Help

[bhuffman]

I have a 97 Seadoo GTI. I replaced all the grey fuel lines and had the carbs rebuilt. The ski was running great until I left the plugs out of the boat. I ran it again after filling it with water and it ran great. Then next time on the water I cranked it and it had this backfire sound and all was dead after that, I cannot get any electrical activity. My battery is new, my ground is good, but I have no gauge activity when I press the start stop button, the motor doesn't try to turn over or anything. I am assuming I have somehow messed up the MPEM 278000916. I want to replace it, if it is the MPEM but I dont know how to test if the MPEM is bad. I have read "NOTE TO TEST YOUR ELECTRICAL SYSTEM AND DETERMINE IF YOUR MPEM IS FAULTY, THE PROPER WAY IS TO UNPLUG THE BLACK/RED WIRE BETWEEN THE COIL AND MPEM. IF IT STARTS AND RUNS FINE, YOUR MPEM OR SWITCHES HAVE A PROBLEM. IF IT DOESN'T RUN, YOU HAVE A STATOR OR COIL ISSUE. NOTE IF TESTING THIS WAY YOU'LL NEED TO KILL THE ENGINE WITH THE CHOKE SINCE THE KILL SWITCHES WILL BE BYPASSED."

Can anyone please be a little more descriptive on how to test to determine if my MPEM is faulty or I have other problems. I have found the Black/Red wire but it is connected to the coil with a black wire, and 2 yellow wires. I have unplugged these four wires from the coil and get nothing when I press the start button. No turnover, no gauges I can't even hear the solenoid click. I have gone into the rear electrical box and can jump from the red wire from battery across the solenoid and the starter engages (motor tries to turn over). The 5 and 15 amp fuses in the front electrical MPEM are not blown also the 15 amp fuse in the rear electrical box is not blown. Please advise the next posssible step... I just want to make sure my MPEM is fried or if it something much easier before I order a new one. Thank you for your help.

Bradford

 

[Dr Honda]

on the 720 engine... the CDI unit is in the coil pack. So... the Black/red wire goes from the stator to the CDI to run the ignition. BUT... there is a tap-in on that wire, and it goes to the MPEM. If you disconnect the wire going to the MPEM, you can start the engine. Be warned... there is be no way to kill the engine other than the choke, or to pull the spark plug wires. Also, there will be no rev-limiter... so don't ride it that way.

But, I'm not sure why you need this test. If you have zero electrical response... then there is a good chance that the MPEM has given up. However... since your ski was flooded... you should check over EVERY electrical connection to make sure there is power getting to the MPEM. It's very rare for an MPEM to die at a random time.

 

[bhuffman]

Red/Black wire cut w/ no change. no start

on the 720 engine... the CDI unit is in the coil pack. So... the Black/red wire goes from the stator to the CDI to run the ignition. BUT... there is a tap-in on that wire, and it goes to the MPEM. If you disconnect the wire going to the MPEM, you can start the engine. Be warned... there is be no way to kill the engine other than the choke, or to pull the spark plug wires. Also, there will be no rev-limiter... so don't ride it that way.

But, I'm not sure why you need this test. If you have zero electrical response... then there is a good chance that the MPEM has given up. However... since your ski was flooded... you should check over EVERY electrical connection to make sure there is power getting to the MPEM. It's very rare for an MPEM to die at a random time.

Thank you for your quick response.

I cut the red/black wire going into the Magneto. I tried to crank the ski and nothing, no turnover no gauges no nothing. I spliced back the red/black wire I cut. I pulled off the Mag housing and everything looked very clean I didn't see any evidence of any water or corrosion I did find a few tiny shards of metal. I did not see any evidence of burned or shorted out wires beneath the Mag housing. I could not visualize where the wires connected to the Magneto. Do I need to take out the flywheel to get to the magneto to check it to determine if it has a good ground? Also I remember that the Rear electrical box that contains the ignition coil and the solenoid were full of water. How can I test the ignition coil and solenoid to eliminate them? The solenoid turns the engine over when I place a screwdriver touching both contacts. Could either the solenoid or ignition coil cause my whole electrical system to be dead? (my gauges, beeps and oil light not to work and to motor not turnover)

I also connected a wire to the negative side of my battery to test different places with my voltmeter. I touched my positive lead of my volt meter to the Metal piece sticking out of the back of the 5A MPEM fuse and I get 0.0volts with lanyard connected and pushing start stop button.

I have 12 volts on one side of the solenoid straight from the battery but have nothing on the other side with the DESS lanyard on the post and the on off button pressed.

Where do I need to check to determine if I have power even going to my MPEM? I ran a new ground from negative of battery up to the front just to test to see if I had 12 volts anywhere. I dont have 12 volts at eith 5 Amp or 15 amp fuses

Thank you for all of your help