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Motorcycle Repair/1982 Honda NU-50


I have a charging problem it causes head & tail lamps to burn
out rapidly, I've put a meter on the contacts at the tail lamp
socket ant it shows appox. 30 volts at idle and goes up to 40
when you speed up the engine. I've not been able to find what
controls the voltage (voltage regulator)
Bn 66


Looking at the parts diagrams for the electrical system, there appears to be only a silicone rectifier in place, no voltage regulator. Generally, in this situation the battery is the load for the charging system, so a fully-charged and load-tested battery is vital to prevent over-voltage conditions.

When the battery is dead or missing the charging system goes to max output and then you get flashbulbs for light bulbs in your scooter.

The ignition is CDI, so doesn't need a battery to run the motor, but the rest of the system DOES need a battery to help balance the charging system output and the electrical load of the lights and to keep the battery charged up.

Bill Silver

Motorcycle Repair

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Bill Silver


Need help with vintage Hondas from the 1960s? I am an expert with 250-305cc bikes in particular and most all of the other pre-91 models, in general. I do NOT claim to have a great deal of experience on Gold Wings, Cruisers, ATC/ATVs and dirt bikes.


I have owned/ridden/maintained Honda motorcycles for 35 years. I have written five books on Honda repairs and collecting. I was a service manager for two Honda shops back in the 1980s.

VJMC (Vintage Japanese Motorcycle Club) of North America

VJMC newsletter, as editor for two years and as contributing editor currently.

3 years auto shop in high school, teacher's aide in Automotive Technology in Jr. College, Diesel mechanic course in college, self-taught mechanic and automotive writer.

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