No spark on '81....bad TCI?

[bennecc]

Ok, I just finished a rebuild of my '81 with TCI ignition. I also rewired the whole thing from scratch. When I finished the wiring, but before I'd gotten any wheels on the bike, I cranked it briefly. Fast forward a few weeks, I put the rest of it back together, but there's no spark.

If I kick the bike over with one plug dangling out of the bike, I see no spark at all. I've tried 3 different new plugs so those shouldn't be the problem. I have checked voltage to the TCI and the coil. Resistance for the pickup and the primary & secondary coil resistance check out fine. According to my Clymers, this would indicate a bad TCI. I hesitate to think the TCI is bad, because it did crank once after the rebuild and I don't believe I've done anything that could have fried it since then.

I was planning on waiting a bit before I shelled out for the Pamco, but I'll just do it now if the TCI is bad. Could the coil be fried? Is there something else I could be missing like a bad ground or something?

I'm at a loss here...

 

[BigJimmyW13]

Man if it is fried It would be time for the pamco setup and a perm mag swap.

 

[650Skull]

Yes they will drop out like that. If you wanted to try and fix the TCI ....Repair of TCI....... a solution

 

[Sundie]

If I kick the bike over with one plug dangling out of the bike, I see no spark at all. I hesitate to think the TCI is bad, because it did crank once after the rebuild and I don't believe I've done anything that could have fried it since then.

Except potentially fry your coil... You can't with a dual-tower coil have one plug ungrounded, even for a moment of firing.

I'd try getting a hold of a new coil first, before contemplating replacing the TCI.

 

[inxs]

- keep something like this handy

 

[bennecc]

Except potentially fry your coil... You can't with a dual-tower coil have one plug ungrounded, even for a moment of firing.

I'd try getting a hold of a new coil first, before contemplating replacing the TCI.

At this point I'm hoping its the coil. But the resistance is within spec, so does that not indicate that the coil is not fried?

 

[Sundie]

No. Because the resistance could still be good, but the insulation could be weak enough to allow a spark to jump.

(Pete will jump in any moment and school me, i'm sure)

 

[angus67]

you said your plug was dangling? It has to be grounded to the motor to fire. thats what inxs is showing. a plug with a clip wlded to it so you can clip it securely to the fins, or whatever.

 

[bennecc]

Well, for the most part I've had the plugs grounded. Although, I have kicked a few times with the plug dangling. Maybe I fried the coil. Although, the only reason I ever took the plugs out is because it was pretty obvious there was no spark because there was no hint of the motor cranking, so I think the problem must be with the ignition. According to the link 650skull gives, the transistor on the TCI is bad. However, several people posted that their transistor tested "bad" according to the post regarding the repair when in fact the TCI worked fine. Who knows. I think I'll just order the PAMCO and hope that cures it.

 

[inxs]

I think I'll just order the PAMCO and hope that cures it.

- has to be a better option than waiting to be stranded where/when you least need it

 

[bennecc]

Just as a followup, I gave in and bought the Pamco. Started right up!

 

[Sundie]

Good on ya!