Total meltdown

[jimcor]

One of the guys from the Winchester, KY Cafe Run fried his bike last weekend. A Kawacker '78 KZ650. Seems he put the wrong size battery in. The friction between the insulator on the + post and the seat pan eventually wore a hole in the rubber cap and he had a dead short across the battery posts. Smoke, fumes, melted wiring, a real mess. Now with a new battery, repaired harness, and a check of all fuses and a visual of other components for heat damage, the bike refuses to start.

He is convinced the problem is in the condensors (points/coil ignition) or coils. I think he missed something in the wiring.

Anyone have any experience with this type of problem? This used to be a more or less common experience "back in the day", never happened to me though.

[BRycraft]

Wiring Problem

After his battery turned into a small arc welder and melted the wiring the problem could lie anywhere in between. How efficient is he at wiring? did he miss or cross a wire, did he solder in new wire or replace the whole harness? Did he use the correct wiring print as his reference for repair? any of these being just the little bit incorrect can and will cause all kinds of problems. Does everything work short of starting like horn, turn signals, lights etc..? if so then I would work at the points and work backward, is he getting spark at the plugs? if not then he could have damaged the start circuit, at least those parts are inexpensive and easy enough to test and replace if needed. I would first make sure everything else is working, if anything is not working properly then who knows what other circuits he might have crossed or not corrected properly.
To give an idea on how much energy is created when a battery is directly shorted, back when I was in aviation maintenance school another student was removing a battery from a small general aviation aircraft when he started removing the positive terminal off the battery before the negative, his wrench while on the positive terminal hit the side of the aluminum fuselage and blew a hole in it the size of a small dinner plate. That battery was larger then a motorcycle battery but direct shorts can be disasterous.
Good Luck Bill

[nabrams]

Befor any conclussions can be drawn about individual components (condensers, coils, igniters, etc.), he should verify whether or not current is even getting to each of those components (measure the voltage with a multimeter at the input wires/leads to each component).

[flyingace]

Refuses to start - as in it won't turn over or turns over but won't fire?

[jimcor]

Electric starter works, horn and lights work. Engine will not start, does not start using the kickstarter either.

[smithbm]

Befor any conclussions can be drawn about individual components (condensers, coils, igniters, etc.), he should verify whether or not current is even getting to each of those components (measure the voltage with a multimeter at the input wires/leads to each component).

I agree completely. He should test the overall circuit and eliminate the good sections as he works his way through the wiring digram. It's quite possible that there is more than one faulty component or wire.

[flyingace]

I have to disagree here. Going thru the wiring system with a circuit tester is tedious and error-prone. I would only do this if the entire bike was dead. Just IMO of course.

You can pretty much test everything electrical by turning on the key and flipping switches. Fix what doesn't work and test your charging system per the stator papers.

As to not starting - begin with spark. Is there? If not, check your coils for continuity and check the resistance rating. If OK, I would swap out the condensors - they are probably fried.