Install Armatures; Adjust Armature Air Gap; Remove Flywheel - Briggs & Stratton 405777 Series Manual

Removing Armatures
1. Remove spark plug leads and spark plugs.
2. Remove rotating screen and blower housing.
3. Remove armature screws and lift off armature(s),
Fig. 1.
a. Disconnect stop switch wires at armatures.
Note: The flywheel does not need to be removed to
service MAGNETRON® ignition except to
check the flywheel key.

Install Armatures

1. Turn flywheel so magnet is away from armature.
2. Install ground wire onto tab terminal on armature.
Note: Make sure wires are routed over armature
mounting posts and away from flywheel.
3. Assemble armature to engine, Fig. 2.
a. Mounting holes in armature are slotted. Push armature
away from flywheel as far as possible and tighten one
screw to hold armature in place.
4. Repeat for second armature.

Adjust Armature Air Gap

1. Rotate flywheel until magnet is under armature lamina-
tions.
2. Place thickness gauge, .008"-.012" (0.20-.30 mm) be-
tween magnet and armature laminations, Fig. 3.
3. Loosen mounting screw so magnet will pull armature
down against thickness gauge.
a. Torque screws to 25 in. lbs. (3.0 Nm).
4. Rotate flywheel to remove thickness gauge.
5. Repeat for second armature.
Note: Route armature ground wire between breather
tube and air horn.
FLYWHEEL

Remove Flywheel

Note: For engines not equipped with fan retainer use
flywheel holder Tool # 19433. First remove
armatures.
1. Place flywheel holder, Tool #19489 on fan retainer with
lugs of flywheel holder engaging slots on the fan retain-
er, Fig. 4.
2. Remove flywheel nut and washer.
3. Remove fan retainer and fan.
2
TSM
Fig. 1 − Removing Armature
Fig. 2 − Installing Armature
THICKNESS
GAUGE
Fig. 3 − Adjusting Air Gap
New Art
#19321
FLYWHEEL
HOLDER
Fig. 4 − Removing Flywheel Nut
STOP SWITCH
WIRES
WIRE
ROUTING