1981 BF75 no spark.

[Kevin J]

BF75 no spark. Have disconnected ground from kill switch to isolate. Oil light will not blink when cranking engine over. How do I troubleshoot CDI? Have multimeter.

 

[jgmo]

Hi,
Check for voltage at the ignition coil primary wire. If there is no voltage then check or bypass the neutral switch. The old neutral switches that have a :"reed" type switch with magnet can get out of adjustment or fail and cause no spark.

Also, spark on these is very faint and checking for spark using the grounded spark plug method can fool you. It's best to try in the dark or under a tarp/blanket to block the light.

 

[rucegra]

Did you try testing the CDI unit by substituting it with a known working one? If the problem persists, it might be worth checking the wiring harness for any breaks or shorts.

geometry dash​