1967 cb160 Not holding charge

You can watch the 3 components just by looking at the battery's input with a voltmeter across the battery posts.

1. Battery: Volts means PUSH so this has to hold volts and have reserve to revert back to its ideal number of 12.8v. Again, to argue the point, I will use Ideal numbers, yours may vary.
a. Battery volts read ideal 12.8v. Key goes on, taillight, dash, coil, spark box, headlight draws from the battery and remains at 12.8v. This shows reserve of a good battery.
b. Battery takes a load test of 'pushing' the starter motor over. When that happens, the voltage drops to 11.1v and returns to 12.8v before the voltage regulator (VR) kicks in. This shows a good battery. Below 11.1v load the battery is bad.
c. Battery can show a surface charge of 12.8v, but can it PUSH? After a full charge and the battery drops past that load test of starting for PUSH, the battery will not hold PUSH, not recover to its ideal 12.8v. The battery is considered junk.

2. V/R: The voltage regulator and rectifier is the middleman between converting AC to DC.
a. When the engine starts, the V/R changes the 12.8v to 14.4v at idle. So you are always looking at the meter to see those numbers move to the next readout.
b. When the meter reads that ideal number, it shows the V/R can convert and regulate that ideal number.
c. When the meter shows past 15v, it shows the V/R is burnt out, and AC begins to cook the acid to where it smells like sulfur and expands the battery case thru excess heat. This will buckle the plates inside and cause damage.

3. Stator: This is the last of the charging loop. You should recognize who is not working to change out what component failed.
a. The meter will change the voltage to 14.4v once the engine begins to run.
b. The battery's 12.8v will change to 14.4v and never go higher than 14.7v.
c. The stator is junk once the engine runs and 12.8v remain steady as the engine revs higher and shows no change.

Signed,
NOLTT (no one listens to turtle)