ive spent hours chasing wires and have not found a short all factory soldered connections have been taken apart and resoldered. connectors that were either broken or burnt have either been cut out and spliced together or have been replaced. right now the bike will run and i can ride it but it will eventually blow the 20 amp fuse. i did install new coils last year and never had a problem untill now. ive had people look at it and they believe that it could either be a coil problem at higher rpms or the voltage regulator could be bad. before i dump money into it i was hoping someone might have an answer to my problem.
It could easily be one or the other of those suggestions. The alternator or reg/rec over charging would be the one I'd lean towards first (assuming you have no shorts of course)
The problem with these old bikes is that they are a minefield of potential problems as they were never brilliant even in the first place.
Check what voltage/amps the reg/rec is shoving into the battery. You also want to check that the battery is holding around 13 volts when it's unloaded, if the battery is goosed - that will also cause you problems.
Yeah, do look for shorts. I had a wire that touched the headlight shell, shorting out. I'd replace the fuse, and was able to continue riding until I turned the handlebars just so, as to blow the fuse again. Finally found it, taped it off, and was good to go.
'77 KZ650C1 - slow project
'78 KZ650C2 Candy Apple Blue, 108,500 kms, 18" wheels front & back, Rickman fairing, Koni shocks, Progressive springs, braced stock swingarm, ATK fork brace, GSXR600 rear sets, SS brake lines, Kerker exhaust, K&N filter in air box, ported, 1st over bore, Kawi electronic ignition, bought in '84.
'78 KZ650C2 - parts bike, another project? 6 #s off.
'79 KZ650C3 - was brother's, now parts bike.
'80 KZ650F1 - parts.
Have you added anything or changed lighting? I changed mine to a H4 Halogen light and things were fine. I changed the 55/60W H4 bulb to an 80/100W and got away with it for years but then corrosion in connections or something started blowing that main fuse. I went back to the 55/60 bulb and problem gone. Kaw didn't build much extra into the system.