Motorcycle Repair: 75 CL360K1 charging system, zero ohms, forward bias

Question
Hi Bill

I bought the subject scrambler a year ago.  I drive about 1/2 hr  once every other month. (I would like to ride more but not until I fix the problem below.) I fixed various issues but one has me stumped. The battery wasn't charging so I'd have to charge it (to keep using the electric starter) every few months. I bought a new battery which didn't fix the issue. I checked the amps to the battery with everything off and its zero. No leakage. I checked the voltage off and its approx 12.3 V and at 5000 rpm its approx 12.1 V with regulator disconnected. I checked the diodes in reverse and forward bias directions and they are open in reverse direction and about 0.9 V in the other direction(Based on the CL360K1 suplement schematic) except for one which was open in both directions. I replaced the rectifier with a new one. The rectifier checks ok now. I checked the stator resistance which measured zero ohms(shorts?) so I replaced the stator with used good stator from ebay.  It now has approx 0.5 ohms W to P and approx 1.1 ohms P to Y. Still approx 12.1 V at 5000 rpm with regulator disconnected. Today, all wires connected (except for the regulator) at the rectifier where the wires enter the rectifier I measure 1.5 ohm P to Y and 12.2 V R/W to engine chassis. Does this sound ok?  Could the rotor be toast? I don't have a oscilloscope so how do I check the rotor magnets?

Any other ideas?

Cheers

Pete

Answer
Peter, you seem to have thoughtfully checked the whole system out very well. The rotor could be weakened and it is difficult to quantify the field strength. With the LIGHTS ON headlight function, there is a good load into the system right off the bat.

http://oldmanhonda.com/MC/WiringDiagrams/MCwiring.php#class   Be aware that the headlight switch has contacts that connect the charging system back to the battery/rectifier. Normally, the headlight switch controls that extra leg when the headlights were manually operated, prior to 1975, but the whole thing got hardwired in 1975. I am not sure if you will normally see the desired 13+ volts at 5k with the lights ON. Can I assume that the battery is fresh and passes a load test okay?

The Pink wire does develop double the voltage of the other two, thus the resistance values are higher.

Where does the charging system seem to reach above break-even?  An amp meter between the battery and either ground or POS would be helpful to see what the amperage is doing, as well.

Bill Silver