Motorcycle Repair: I just want to ride! all I need is for the battery to charge, fresh paint, voltage regulator

Question
Bill I have a cb350 a 73, live and learn.
It had been half brain (best way I could put it and still be kid friendly) restored when I got it. I have had it now 4 years. It had fresh paint, new tires and brand new carbs when I got it. They had upgraded from original carbs with a nice set of Minuki's, but the bike would never hold a charge. Sitting in storage for nearing 2 and a half years, I came across the opportunity to buy another one just like it the guy told me it was a cb350k, I believe. The book shows a could different wiring diagrams, not the one he mentioned though, he may have been wrong too. I found a manual under the seat and it says it's a cl350, none the less after riding it for five minutes, I told him I'd love to have it for parts (no title#, but I needed it only if it charges the battery. Gave me his word it did, I should've tested that, simply by riding it for an hour at the time or later. Before... I had swapped out the stator/alternator #outside coils only), rectifier, and voltage regulator. I now have the same problem. Am poor student have no more money. I dropped it yesterday while towing it home when it broke down, I now have a big dent in the beautiful tank. Found the strap after the fact. Hurt myself next. You see my aggravation here Bill?
    I read what you wrote about any more than idle will put out 40 volts or more ac, on the pink and my yellow wire and I understand it may be the rectifier or voltage regulator too. I just about eliminated any chance of the wiring being wrong with the aid of the cb/cl us 350 diagram. I would think I need the voltage from those two wires from the alternator before anything. Do I tough the black and red probes on pink and yellow at the same time, or the red to one at a time with the black probe grounded? and how would I go further to test the rectifier and regulator? Can ya help me Bill? All I wanna do is ride it!

Answer
I happened to read more of the followup notes on your question.

The "forgot to mention" section is critical information left out.

The headlight switch routes the extra stator phase back to the battery when the lights are on. Leaving the switch out of the circuit cuts out a portion of the charging system output. Try putting the yellow/yellow white wires together up in the headlight section of the wiring to increase power output.

Bill Silver


...........................................

Michael,  Sorry to hear about your latest round of woes on the 350.

Basically the CL and CB350s are the same machine with the same wiring connections and charging systems.

The AC voltage can be verified or measured, one wire at a time from the stator. If you just probe the yellow, brown, pink wires at idle you should see a 12v test light brighten up with the pink wire about 2x bright as the other two. Be sure that you have clean and shiny wiring connections throughout the bike's electrical system. The stator output is in AC volts, which are rectified into DC volts, then routed back to the battery.

Also on the 350s, I think they have a small green wire in addition to the ground lead to the battery, so be sure both are connected. The small wire grounds the harness to the chassis.

Beyond that, you might try to leave the current regulator disconnected (small box beneath the battery tray with yellow/black and green wires) to see if the voltage output increases. If you run with the lights on, then go into the headlight shell and check to see that the headlight dimmer switch wires are all connected properly. When the lights go ON, the extra coil in the stator gets included into the power output. Those are yellow and yellow/white wires. Sometimes when the bikes sit for a long time, the internal contacts in the headlight switch can corrode and fail to make proper contact.

Test the rectifier with an ohm meter to verify that there are no shorted/open diodes. Go from the output wire(red) to each of the other diodes with the ohm meter and then reverse the leads to see if you get different readings. Basically you want to see low ohms in one direction and high to infinite in the other polarity test.

http://oldmanhonda.com/MC/WiringDiagrams/MCwiring.php

Always test the charging system with a fully charged, load tested battery.

Bill Silver