Nissian 40hp - ignition switch??

[mch2184]

Changing out ignition switch on a Nissan 40hp - need help identifing wires (no manual).

exsisting wires from old ignition are:

one brown
one black
one blue
one green
two red

None are labeled

new ignition switch is labeled as follows:
I - ignition circuit
B - + batt.
M - Magneto
C - Choke
S - Solenoid
M - ???

THANKS

STEVE