no spark

[Bkeeper]

I have a Nissan NS 9.9 B2 electric start which was running beautifully until I started it without the cables connected to the battery. They were coiled up and wrapped so the ends would not touch each other. But while the engine was running one of the cables must have come close enough to a bolt on the transom to touch (or arc) and the engine stopped and now wont start again. What component(s) did I fry?

 

[pvanv]

Typically, that would blow the fuse. If the rectifier went dead short before the fuse blew, you could damage the CD. Diagnose the ignition system, and cross your fingers. That model is very obsolete, and many parts are hard to come by.

 

[Bkeeper]

Thanks for that, Paul. The fuse (there seems to be only one) is in tact. As far as I can tell it was the black (negative) cable that touched the transom. So it would have been ground to ground. Does it make sense that it should have done anything at all?

 

[pvanv]

Nope. It was coincidental. Time to get out the analog meter and start testing ignition components.

 

[Bkeeper]

Did some testing as you suggested. The kill switch is ok. The resistance on the stator coils - blue/black = 60 (optimum 30-46); red/black = 270 (optimum 168-252), so both are above the max for the range given. Voltage on the other hand came in low - blue/black = < 1V, (minimum 4 V); red/black = < 20 V, (minimum 110); black-yellow/eng. ground = < 20 V, (minimum 110 V). Given the low voltage output, would you say the stator/trigger coils are toast?

The testing info I got from this website http://www.**************/productcenters/electrical/Tohatsu-Nissan.pdf. The only part I did not understand was the heading over the voltage "DVA Connected". DVA = dynamic vibration absorber as far as I can tell. Has it any bearing on my voltage test?

 

[pvanv]

DVA = Digital Voltage Adapter. You need that function to see the very brief pulse from the exciter, etc. Of course, you could use an oscilloscope to read the peak. Your analog ohm tests are not too far off. If you use an analog meter with battery of 3v or less, you can use the ohm tests for the CD in the Factory (not aftermarket) service manual.