No spark

[JohnMC]

I have a 85 vintage JD 316 with Onan B43E engine. No spark at the coil/plugs. I have 12v at the coil and test light blinks slightly on negative side of coil while cranking. Points look good & will spark/arc slightly when I insert a feeler gauge w/ign on. Not sure how to check condenser. Check fuses & connectors at ign switch & downstream in the wire harness. I also just noticed that the points don't move when cranking engine. There is a small pin under the points plate that is supposed to cycle the points open/closed. Does anyone know what the length of that pin should be? Terminals are clean. Anybody have any more ideas before I buy a new coil? Thanks.....

 

[Willl]

I also just noticed that the points don't move when cranking engine. There is a small pin under the points plate that is supposed to cycle the points open/closed.

I've seen those pins get stuck after engine sitting long time.

Use q-tip to get very small amount WD or some other penetrant oil around pin and work it loose.

 

[JohnMC]

Finally fixed it. The points weren't moving because the baseplate that the points attach to wasn't positioned correctly causing a side load on the pin & keeping it in the up position. Once I centered the baseplate the plunger moved freely. After that I diagnosed a bad coil. New coil & all is well.