Ok,
Meter on DC V
Key on/ignition on
Black probe battery negative post
Red probe battery positive post
Note voltage
Note-back probe the ignitor connector from the ignitor side. This will rule out bad connector terminals. Also leave all connections connected. Voltage drop tests need the circuit complete)
Move red probe to the black/yellow wire in red circle(connector for the ignition system ignitor. Possibly hiding under a side cover)
Note voltage
Should be 0 volts or very close. Any higher than 0.5V then you have a big voltage drop on your yellow/black wire which is a ground wire.
Move red probe to red wire. Should be close to battery voltage.
Move red probe to green wire in red circle. Crank starter.
Note if voltage fluctuates between 0 and battery voltage.
Move probe to black wire in red circle.
Crank starter.
Voltage should fluctuate between 0 and 12v.
The 0v should just be a blip. It will mostly be 12V. Same with the green wire above.
Green circle time.
Meter on AC V
Red probe on red wire
Black probe on yellow wire.
Crank engine.
You should see an ac voltage of a couple of volts as the engine turns.
Green circle connector again
Red probe on blue wire
Black probe on black wire
Crank engine.
Note AC voltage.
Turn off bike
Schematic courtesy of angie(biker_gal_uk)