1999 90 ELPO ...no spark

mikeneal

Senior Chief Petty Officer
Joined
Jan 28, 2004
Messages
710
Yesterday my 1999 Mercury 90 ELPO just shut off. I checked it slightly while offshore and had no spark. And messed with it some offshore trying to troubleshoot it and then weather was turning and I threw the flag called TowBoatUS. (have the coverage)
I disconnected the kill switch circuit and still nothing. Disconnected the main 7pin connect from the motor and jumped the starter and still no spark. I think that eliminates all boat wiring /kill switch/ignition switch right? The boat had sat for several months but ran a couple hours earlier in the day perfectly.
No spark any three cylinders. I unplugged the yellow wires from rectifier and still no spark. I checked the green/white and white/green wires of the stator because something I found on the web says that should 400-600 ohms. It reads open.

Disclaimer: I had a poor understanding of the magneto ignition while on the water and inadvertently/foolishly put +12V on the kill switch thinking is was like the I/O things I have owned in the past. It had no spark prior to my screw up, but I might have hurt something else too. I have what I though was a factory manual for the motor but it shows a switch box and unless I am an idiot I cant find a switch box. So either (A) I am an idiot, (B) I have wrong manual and there isn't a switch box or (C) all the above.

Any thoughts from the pros? Thanks in advance for any help you might be able to provide.
 

schematic

Lieutenant Junior Grade
Joined
Jan 12, 2008
Messages
1,102
Re: 1999 90 ELPO ...no spark

Sounds like the original problem was your stator. Go to CDI electronics http://www.cdielectronics.com/downloads/troubleshooting guide/ and download the appropriate guide for your motor. Follow the instructions to properly check your system.
You may also have damaged the switch box. Verify and replace the other damaged components first. If spark doesn't return, then replace box.
 

mikeneal

Senior Chief Petty Officer
Joined
Jan 28, 2004
Messages
710
Re: 1999 90 ELPO ...no spark

Ok, so I think I have a newer CDM in the coils without a switch box.
 

schematic

Lieutenant Junior Grade
Joined
Jan 12, 2008
Messages
1,102
Re: 1999 90 ELPO ...no spark

you are correct, you should have 400-600 on green/white and white/green wires.

stator is open. replace it
 

mikeneal

Senior Chief Petty Officer
Joined
Jan 28, 2004
Messages
710
Re: 1999 90 ELPO ...no spark

Called CDI tech line and the guy was super helpfull. He asked about boat baggies which I though was odd question but I have 2 maintance free one of which is old and not much good. For some of the day I ran it on that battery and he claims a aged maintance free battery will severely overload the stator and he bets I killed the stator and the possibly the rectifier. :-(
 

mikeneal

Senior Chief Petty Officer
Joined
Jan 28, 2004
Messages
710
Re: 1999 90 ELPO ...no spark

So replaced the stator and it runs. I also replaced the old dying maintance free battery and now have two new "capped" batteries. A local shop sold me the stator for slightly over cost and popped the flywheel off for me. Low and behold when I went to remove the stator 2 of the bolts were sheared off and a 3rd the threads in the boss were suspect. I drilled and tapped them and installed helicoils. Interesting, maybe vibration? I have owned the boat 3 yrs and it hasn't been apart since I have owned it.
 
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