no spark mystery

[nahcotta]

First the history of the problem. I have a 1980 70hp evinrude that has ran like a champ for the last two years. Two weeks ago while crabing in the bay my motor died. I had to use the kicker to get it home. Once home I found I had no spark to the top or bottom cylinder. I happened to have a new powerpack (just in case) I put it on to see if it would make a difference. Still no spark. I then lessened the gap in the spark plugs to .35. At that point I got spark in both the top and bottom. These were new plugs installed 1 1/2 months ago. I put the boat back in the water and off I was.<br /><br />A week later I get into my boat to start it and again no start. I immediately checked for spark. When I pulled the top plug out and turned the motor over, the motor started. So i put the top plug back in and tryed to start it agian. It still would not start. So I pulled the boat out of the water and again checked for spark in all plugs. NO spark in any of them.<br /><br />HERE IS WHAT I'VE DONE<br /><br />Checked for spark on all plugs. NO spark<br /><br />Checked primary coil resistence, on each coil with ohm meter. It is 0-1 ohm. <br /><br />Checked secondary winding ressistence, on each coil with ohm meter on high ohms. It too reads 0-1 ohm. But on low ohm setting it reads 300-250ohms<br /><br />I do not have anytools to check the powerpack.<br /><br />I have tried removing the yellow and black wire from the 4 wire plug that attaches to the coils 4 wire plug, from the power pack. Still no spark<br /><br />I have tested the timer base at the four wire plug. Wires A & D have 20 ohms at low ohms setting. Wires B & C have 30 ohms at low ohms setting. <br /><br />I have put on a different timer base and it too has the same ohms readings on the wires.<br /><br />I have also tried removing the rectifier wiring. Again no spark when the rectifier is removed. <br /><br />HERE ARE MY QUESTIONS.<br /><br />Does anybody have any ideas of things that I might be missing.<br /><br />Are my coil reading within normal limits.<br /><br />Any suggestions?

 

[Joe Reeves]

Re: no spark mystery

Pertaining to the spark.... with the s/plugs removed, that spark should jump a 7/16" gap with a strong blue lightning like flame. Don't check the spark by using the spark plugs as test equipment.<br /><br />In removing the black/yellow wire from the pack, you eliminated the wiring harness and the ignition switch circuit. This indicates that the problem is at the engine itself.<br /><br />The beginning of the ignition system is within the stator assy under the flywheel. The stator is a two fold component... small coils to supply ac voltage to the rectifier for the charging system, and three larger coils which supply approximately 300 AC volts to the powerpack.<br /><br />It sounds like the stator has failed in the section that supplies the AC voltage to the powerpack. Check the stator visually to see if cracks are present, and also to see if there is any sticky substance dripping down from it to the timer base and block. If this is the case, replace the stator.<br /><br />Even if the stator looks fine, with an ohm meter check between the brown and the brown/yellow wire. You should get a reading of 550 ohms - + 75 ohms. There should be no reading between either of those wires and ground.

 

[kellytime]

Re: no spark mystery

Thanks Joe for the info. First off this is still me Nahcotta. I"m at home and have a different log on name at my home computer. I always forget my passwords. Anyway.<br /><br />First off I did inspect the stator. There were no bubbling marks, and there was no plastic dripping onto the engine block. <br /><br />I did an ohms check between the brown and brown/yellow wire. I did get a reading of 550 ohms. I also check between the brown and ground and got the ever so slightest of a reading when I really scratched at the block with the ground prob from my multimeter. Does that mean my stator is dead.<br /><br />Tell me what to do next? I'm all ears. Can I bad stator mean a bad powerpack also? I'm really worried about having to replace all ignition components stator, timer base, powerpack, and three coils. Could they all go bad at once?<br /><br />Thanks for help.<br /><br />Matt

 

[kellytime]

Re: no spark mystery

For all of you following my problem I have found the fix. It did indeed end up being a faulty stator. Replaced the stator and the magic spark can back. Thanks Joe for pointing me in the right direction. This forum is the best.<br /><br />Matt