Topic: Anybody know about CM400 electronics?

[Jore]

Hi guys, I'm asking here because the hondatwins hasn't been that helpful with my inquiry. I'm helping out a buddy rebuild his 1980 cm400, darn bike ran when parked about 3 months ago. Now that we've rebuilt it she won't run, well to be specific, there's no spark on the damn thing. There's a procedure where you check the resistance between some wiring for the cdi module and the ignition coil, everything checks within tolerances, and if you connect the voltmeter to the ignition coil plug and hit the starter button you get pulsed voltage, so there's definitely a signal going to the coil, thing is with one spark plug inside the head and the other grounded laying on top, if  you hit the ignition button there's no spark, nothing!

What can i try?

[strynboen]

is there a ignision or(power) or ground key konnektion you have forgotten..the stop button..cant renember if it brakes or gives konnektion

..there is a impuls coil  and a cdi module..its a veak point on 1980-90 bikes

[Jore]

is there a ignision or(power) or ground key konnektion you have forgotten..the stop button..cant renember if it brakes or gives konnektion

..there is a impuls coil  and a cdi module..its a veak point on 1980-90 bikes

Everything checks out correctly, there's a wire that grounds the whole system and cuts the spark, but it's disconnected at the moment.

This is the wiring diagram we are using on that bike:

[MoMo]

Do you have 12 V at the black white wire?


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[Jore]

Do you have 12 V at the black white wire?


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according to the honda twins forum, that wire should be disconnected, and if you ground it it kills energy to the cdi