Service Manual

33
IGNITION SYSTEM
At slower speeds, the flywheel ma
g
net induces a
smaller char
g
e in the tri
gg
er coil. This action tri
gg
ers
the silicon controlled rectifier (SCR) enablin
g
easier
startin
g
in a “retarded firin
g
position” about 5 de
g
rees
before top dead center (BTDC). (See Fi
g
ure 50.)
Fi
g
ure 50
3297-018
At faster speeds (about 800 RPM), the flywheel
ma
g
nets induce a lar
g
e enou
g
h char
g
e in the tri
gg
er
coil to tri
gg
er the SCR in the “advanced firin
g
position”
(about 28 de
g
rees BTDC). (See Fi
g
ure 51.)
Fi
g
ure 51
3297-019
CD Pack Air Gap Adjustment
1. Rotate the flywheel until the ma
g
nets are directly
adjacent to the CD Pack as shown. (See Fi
g
ure
52.)
Fi
g
ure 52
lbv0040a
2. Adjust
g
ap by loosenin
g
screws, insertin
g
Lawn-
Boy
g
au
g
e (P/N 604659) or a piece of .010" (.25
mm) shim stock and ti
g
htenin
g
screws. Remove
the shim stock or
g
au
g
e.
CD Pack Removal/Installation
1. Disconnect leads and remove mountin
g
screws.
2. Replace CD Pack, and set
g
ap as outlined in step
1 above. Ti
g
hten screws. See specifications for
torque values. (See Fi
g
ure 53.)
Fi
g
ure 53
lbv0040b
A. Pole Shoe
B. Flywheel Rotation
C. Crankshaft at 5° BTDC
D. Ma
g
net
E. Startin
g
Le
g
F. Char
g
in
g
Le
g
G. Pole Shoe
A. Flywheel Rotation
B. Crankshaft at 25°
BTDC
C. Char
g
in
g
Le
g
D. Runnin
g
Le
g
25°
Advance
.010”
(.25 mm)