6 Volt Coil Test
I noticed a few people wanted to know how to test a questionable ignition coil. Here's what I do to check a 6 volt coil . Using your sparkplug rig (clean ,brand new , known good plug clamped to a ground wire or a battery clamp for a ground ) Connect a brand new 9 volt battery to a couple of short wires and ground the (-) to the coil body and momentarily make and break the (+) to the coil primary connection . ( I just grabbed some wires for the pic , yes I know I have a black wire connected to the (+) It already had a female tab connector so I used it) There should be a decent enough spark that's visible at the plug. I imagine a micro switch or whatever you have in your junkbox could be used to make a more permanently test rig to test a coil . Don't forget to ground the coil pigtail if there is one (small thin white wire coming from the coil body ) You must make/break on the (+) coil contact not the gound otherwise it won't spark. OR if your lazy You can also just leave the coil bolted on your bike , ground the test-plug and hook a 9 volt to ground and momentarily contact the (+) wire to the coil . The disadvantage of leaving the coil bolted on is that the coil may not be cleanly grounded (as in rusty) in which case- no spark -so doing it off the bike is the way to go . Obviously for a 12 coil use two 9 volt batts connected in series. If you have a CDI system - don't do this with the box connected , you just want to check the coil for a working collapse of the field.