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OK, been reading in this forum for about 8 mos now and have found it EXTREMELY beneficial! Thanks to all who work the site and reply to issues. I have a 1976 KZ900 LTD my father-in-law GAVE to me after he bought a newer bike. He and his brother (trained motorcycle mechanic) had taken this one down to the frame and built it back, almost original. I took the bike (it was running, just had to kick start, the electric start button was bad, the bike had sat out in the elements for about 6 mos after he got the newer on). I really wanted for a hobby, but the price of gas had driven me to want to use it for a regular comuter vehicle. I am military, had to take the safety course on post so I put a new battery in and new coils and wires, and new plugs drove it a couple of afternoons for 30 min or so and then went to the course. Made it thru half the day (bike only ran for maybe 30 mins total of the class) and it wouldn't start. Took it home, charged it up, went back the next day and it ran all day until the very end and the same thing happened. Each time the plugs are fouled with carbon, not oil. I figured I have a charging problem, trouble shot the stator (IAW the shop manual thanks to whoever posted it!!) and was getting 25-29 out of the stator. Trouble shot the recitifer, found it to be bad, found a new one at a local junk yard, tested good. I installed it, still only 12V at the battery. Tested the new rectifier again, showed bad. Then tested the regulator and it showed bad. Could the regulator being bad had blown the rectifier? I don't mind spending the money for a new rectifier/regulator combo, but not if something else is blowing them? Don't know where to go from here, any suggestions would be good. I'm sure I haven't provided enough data, but this is lengthy enough as is, but I would appreciate any assistance you might can provide, I really need to get this thing going, runs great until it starts losing electrical, then fouls and won't start. BTW, did get the electrical start cleaned up and working, so there is no short in there. Thanks in advance and appologize for my novice ignorance of the bike, and any forum rules I may have violated, but I'm trying!

Eight months of lurking! WOW! I recall taking the military drivers license test with a bike in 1972 on the island of Okinawa. It was during a typhoon condition and I was blown 20 feet off the test track which was painted on area the size of a basketball court as I recall. The person who was testing me let me start over, I got my license and rode home in a torrential downpour and near typhoon winds. I was younger then and riding a DT125 dirt bike. I was also smarter then. I have gone downhill since that point radically but I digress!

OK... KZ900. The 25-29 per leg out of the stator wasn't all that terrible. The bike would have run fine. The stator terminates in a blue plug that connects to the blue connector in the patch panel on the left side of the bike. The wires OUT of the patch panel connect in parallel to the GREEN connector which is the regulator and WHITE connector which is the rectifier bridge. They come out and join at a 2 into 1 connector that splits and goes to the battery and main fuse. If you get 12VDC at the battery at 4K rpm, the rectifier bridge IS working otherwise you wouldn't have DC here. The problem is with the regulator. Since you have SWAPPED the regulator, let's pretend the first one was likely good. The regulator connects to the stator via the 3 yellow wires coming off the stator in that patch panel. Clean the connections for all the wiring I have mentioned using spray electrical contact cleaner and dab them all with dielectric grease to prevent corrosion. I have already mentioned the heavier gauge white wire coming off the regulator. It goes into that double connector with the wire from the rectifier bridge and coming out a wire is going to the battery terminal where your hot battery cable is and also another leg comes out and goes to the main fuse. Get these connectors all clean and greased in the same manner. OK... you still have a BLACK wire and a BROWN wire coming off the stator and they are just dangling. The BLACK wire is ground and will connect to a ground wire coming off the solenoid. If you can't find that wire, the solenoid has been swapped so ground the black wire from the regulator to any solid frame ground. A good ground is critical. Make sure that the MAIN ground from your negative battery terminal is GOOD. It should be on the engine case by the kick starter. Last is the brown wire. This wire senses voltage on the main harness and is what causes the voltage on your regulator to adjust. Since you are not seeing this adjustment as rpms rise as you check at the battery, find the red wire that powers your brake running light. Take a long piece of wire and connect the BROWN wire from the regulator to the red wire from the running light and repeat the DC voltage test at the battery. Idle should see 12VDC and 4K rpm 14.5VDC. If using the red wire rectifies the problem, the problem is in the brown subcircuit. It is disconnect somewhere between the ignition switch and where you plugged it into the regulator. Last, the tests for the regulator can easily show misleading results and the test at the battery and some extrapolation provide an easier to figure out troubleshooting route. Good luck and don't wait 8 more months to post! wg