75 350B factory voltage regulator question

[rdsarefun]

Had a question about the factory voltage regulator for a 75 350B. Does the adjustable metal contact (portion that is bent using pliers) actually touch the thin sheet metal spring steel to make contact when bike is not running and turned off or is there a gap between this and the thin sheet metal?  I adjusted as mine was overcharging *(by bending this tab downward) and now it wont charge- -may have went too far, thinking it may need to contact or a specific gap needs maintained.  Would anyone have a picture of this, looked in factory service manual and it states to move this but no close up pic.
  Thanks, Brian

[1976RD400C]

The metal tab you bend to adjust should touch and load the piece of spring steel. That is closing the electrical contact on the other of the coil and giving the alternator field coil (the rotor) voltage and magnetism. That is causing the stator coils to produce voltage (when running). Battery voltage is running through the coil in the voltage regulator and when it gets high enough the magnetism pulls that plate, above the coil, down. That plate is fighting against the pressure you have put on it with the bendable tab pushing on the spring steel. When the voltage is too high, coil pull plate down, contacts break open on the other side and stop supplying voltage to the field coil (rotor), reducing the output of the alternator. That is happening very fast, keeping the rotor voltage exactly right so it is charging at the exact right voltage. The more you bend the tab up, the harder it is for the coil magnetism to pull the plate down, thus the rotor is staying on too much and alternator output voltage is going to be higher. The less pressure the spring steel has, by bending the adjuster tab down, the less the output voltage will be because it is easier for the coil to break the contacts.

[rdsarefun]

Thank you for the reply and photos, will work on this weekend.

[IR8D8R]

Very thorough description here including setup and troubleshooting:

https://www.scribd.com/document/533947248/Yamaha-RD350-R5-RD-350-Electrical-Wiring-Diagram-Schematics-1970-to-1975.

 There are several charging "stages" where power to the fields is varied by resistors at the regulator to control the charging output, switched by the magnetic coil via several contact points. I don't think that power to the field coils is ever interrupted. Unless the ignition is off.

IR8D8R