81 XS650 lost spark

[oldcoal]

Had it running the other day when all at once it died. Pull the plugs out to check for spark and have no spark to either one. Pulled gas tank off and pulled the plug going to the coil. One wire has battery voltage on it all the time and the other one has no voltage on it. How do I trouble shoot this and also is the ignition parts in the alternator area?? So is it likely to be the coil or is it the electronics pickup
THANKS

 

[figure8]

It's either your coil or the tci box which is directly under the battery box.

 

[gggGary]

or the pickups or wiring in the LH cover or a crapped out fuse box or....

 

[retiredgentleman]

Sudden loss of power......................that is the classic characteristic of the dreaded fuse panel failure. If your bike still has the original 4 position (glass fuses) fuse panel, its worn out and must be replaced. Automotive blade type fuse holders work amazingly well.

 

[oldcoal]

Sudden loss of power......................that is the classic characteristic of the dreaded fuse panel failure. If your bike still has the original 4 position (glass fuses) fuse panel, its worn out and must be replaced. Automotive blade type fuse holders work amazingly well.

I might agree with you if I had not checked them and found they all have power on each end so unless the ends where the wires are solder on are have poor connections that could not be the problem. But I might just try jumping across them and see if any thing changes

 

[gggGary]

give a us a hint of what the bike is stock bobbed etc? pic of the LH side?

what is your battery voltage? turn key on then off while watching plugs. (both plugs MUST be grounded for all spark tests and any time you crank the engine) do you get a spark when you turn the key OFF?

 

[oldcoal]

give a us a hint of what the bike is stock bobbed etc? pic of the LH side?

what is your battery voltage? turn key on then off while watching plugs. (both plugs MUST be grounded for all spark tests and any time you crank the engine) do you get a spark when you turn the key OFF?

Bike is pretty much sock other then a couple add on rear turn signals which are going to be removed. Battery voltage is around 12.5 volts which means it is good. There is no psark at all not even when you turn it off and on. Have both plugs laying on the engine so should be good enough ground to make a spark

 

[retiredgentleman]

I might agree with you if I had not checked them and found they all have power on each end so unless the ends where the wires are solder on are have poor connections that could not be the problem. But I might just try jumping across them and see if any thing changes

Those old clips that hold the fuses can be high resistance, so may appear to have voltage but unable to pass required normal current. Regardless of you seeing voltage, you should replace the fuse panel.

Other items to check are the kill switch and the ignition switch. They can have high resistance also.

The TCI black box (ignition) may have just quit. Other possibilities...............the TCI pick-ups that are on the alternator.