Originally Posted by danatack

over twenty years ago i remember the same thing happend on my 85' tri-z, it ended up being the coil, is was 13 then so bare with me. i remember it eating pluggs, i had small town sponsorship through our yamaha shop and the mechanic told me he replaced the coil... wow long time ago. any way they say to test the cdi with a known good component rule. that always told me they don't know how to test one lol. i wouldn't worry about a book just yet. ck-to make sure stator, coil, etc. have good component grounds, the stator sends a pulse signal to the cdi, you would notice a wire coming out of the stator pulsing your test light dimly but steady. current goes to the (pre-mapped) cdi. each cdi has been designed with a spark curve, and rev. limit for that specific machine, then current goes to the coil were the coil is just one big resistor, or capacitor(gathers and holds an electric charge), generates a healthy spark20 to 60kv exp. then goes through the hi-tension lead to the spark plug to ground.

Originally Posted by danatack

over twenty years ago i remember the same thing happend on my 85' tri-z, it ended up being the coil, i was 13 then so bare with me.

Originally Posted by Raptor450

It must have been the ignition coil, it's running again. The sparkplugs that I thought were dead now work with the new coil, so I guess the old coil was giving out instead of the plugs going bad.

Originally Posted by Unknownquad

Raptor 450 if you still have that old cdi unit and it works, i can take it off your hands. Same thing happend to me so i took it off and it was run over. Nightmare!!! let me know, Thanks