TOHATSU 40 Service Manual page 193

SECTION 7
Magneto
For models 40 / 50 / 60 / 70 / 80 / 90 :
The magneto consists of a cover (1), flywheel (2), and coil
4
plate assembly (3), guide plate (4), shim (5), and set ring (6).
Mounted radially inside the flywheel are a series of high-performance
ferrite magnets. The boss, located in the center of the flywheel, is
keyed to maintain proper alignment with the crankshaft. The
flywheel is plated to help prevent corrosion.
The coil plate assembly consists of an alternator coil set (7), exciter
coil set (8), and pulser coil set (9). The alternator coil set provides
charging voltage and will be discussed further in the charging
system description.
For models 115 / 120 / 140: The magneto has similar
5
components except, the pulser coils (1) are on a separate
assembly called the pulser coil assembly (2). The alternator (3) and
exciter coils (4) are on an assembly called the alternator assembly
(5).
Exciter Coil Set
The exciter coil set consists of many windings of wire wrapped
around a metal lamination. Once the flywheel exceeds a minimum
cranking RPM, the lines of force from the ferrite magnets cut
through the exciter coil windings to produce about 150 DVA (peak
voltage) at cranking speed. The output from the exciter coil set is
used to power the CD Unit.
60B and 70B engines have two exciter coils; one activates at
speeds up to 1700 RPM and both coils are activated at speeds
over 1700 RPM.
7-14
T1456
T1457
3-/ 4-Cylinder