After 2 months of slowly dying.... my bike wont start. No spark

butterbeats

XS400 Addict
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After 2 months of slowly dying.... my bike wont start. For months the battery would not recharge. I checked rectifier, tested ok. Replaced fuses. Cleaned carbies. Yesterday took out starter and starter motor brushes checked and cleaned. Starter was filthy but cleaned up well. I tested for spark and no spark out. I have just installed new spark plugs, Battery new, and recharged after being run down. I tried new ignition coils but still no spark and they heated up really quickly and really warm. I put the old ignition coils back in.

When I start key ignition, starter kicks in but doesn't fire up. Sounds like no spark firing up. There is fuel getting into carbs.

Does not jump start either??

Any ideas??
 

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Check for shot wires. If you look behind the chain, there is two bundles of wires going out of the bottom of the engine, heading up to the under the seat. Right where the wires come out of the engine, squeeze those wires. If you feel snap, crackle, pop, and you dont' see breakfast cereal near by, your wires are shot. if that is the case, look in the Tech section, and there is a post marked rewire. let us know if this was a miss diagnosis.
Tobie
 
Points I believe 1978 XS400...

Have you checked the points? Maybe a good filing and setting the gap will do for the no spark situation. Even if the bike isn't charging, with a charge in the battery, you should get spark. If the coils are OK and the points are OK, look at the condenser.

As for the not charging, there's a bunch of threads on that. I had that issue myself.
 
So last week I redid allot of stuff and when I redid the leads connecting to my ignition coils and spark plugs my bike kicked over. Battery did not recharge though so I am going to replace regulator. I finally have some time today and I will go over wires and points as you suggested. cheers.
 
Just replaced the condenser and that has seemed to help with the recharge problem. The new condenser had different connections to the old condenser. As you can see in image provided. Had to reuse old plastic coupler set/ wire holder as I could not get a new one which matched the old coupler.

Today was first morning where it has been starting first go without a problem. Usually it was 50/50 if it would start, at very best.... I have ordered new rectifier NOS after debating whether to replace a unit which tested ok. What the hell it was only 6 months debating and $150.
 

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After another week of never being sure if the bike would start, I finally replaced the rectifier with a NOS one that cost around $140 US with postage and finally seem to be starting first go.
 
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