The igniter of Suzuki AN series (Neptune belongs to AN series) also integrates the heating function of carburetor (not the electric control air on the carburetor, but another heating resistor on the carburetor, and the heating function was cancelled in later models). Its connection mode is basically as follows:

Orange-Power cord

Heater connected in black (skip this line if carburetor has no heating resistance)

Yellow/green start switch

Stator trigger coil of white magneto

Blue/white-high voltage package

Black/white ground

Braun magneto stator trigger coil

Green side bracket (small bracket) switch (some have cancelled this switch)

Here's the thing. You can compare it.