Cessna 177 SERIES Service Manual page 168

housing. There are four timing marks cast on the NOTE
rotating magnet. two on each pole piece.
When the
rotating magnet is in its neutral position and then ro- Extreme care must be exercised in this
tated in normal direction of rotation, the first timing operation. If cam adjustment is changed
mark on rotating magnet to appear in ventilator hole in the slightest degree, the timing of the
is the "E" gap mark for magnetos of this rotation. magneto will be thrown off. Do not drive
The other mark on magnet is the "E" gap for mag- cam on shaft with a mallet or other instru-
netos of opposite rotation. ment.
5. While holding rotating magnet in this EXACT
location, adjust the breaker contact points to just
12. Repeat steps 3, 4, 5 and 6.
begin to open. Point opening shall be determined by
the use of a timing light. (Bendix Part No. 11-9110 c. BENDIX D-2000 (DUAL) SERIES. (MAGNETO
or equivalent.) REMOVED FROM ENGINE.)
6. Turn rotating magnet in normal direction of
rotation until cam follower of contact assembly is on NOTE
the high point of cam lobe.
Contact point clearance
should be 0. 016=0. 003 inch. If dimension does not A magneto, correctly timed internally, will
fall within limits, readjust contact points and recheck have the red painted tooth of the large dis-
to be sure the points just begin to open when the appli-
tributor gears approximately centered in the
cable timing mark (refer to step 4) on magnet is
timing windows, the L ("E" gap) mark on
aligned with divided casting line on housing ("E" gap).
the rotor shaft in alignment with the pointer
and both sets of breaker contacts opening,
NOTES
all at the same time.
Wire feeler gages are recommended when 1. Remove breaker contact point assembly
checking contact point clearance, cover, if installed, by removing the cover screws,
pulling cover directly aft away from housing and dis-
* No attempt should be made to stone or dress
connecting both capacitor leads from breaker contact
contact points. assemblies.
2. Remove timing inspection hole plugs from
* If the above conditions are met and within magneto.
tolerance, the magneto is timed internally 3. Slowly turn the rotor shaft until the red
and ready for installation. If the above
painted tooth of the large distributor gear for each
conditions are not within tolerance, proceed side is approximately centered in the inspection
to step 7. windows and the L ("E" gap) mark on the rotor is
aligned with the pointer. Lock the rotor in this
7. Using a pair of padded jaw pliers or a vise.
EXACT position using Bendix Rotor Holding Tool,
grip the drive member on the drive end of rotating Part No. 11-8465 or equivalent.
magnet. While holding the rotating magnet, loosen
the screw securing breaker contact cam to rotating NOTE
magnet shaft and back screw out approximately half
way.
Place the end of a broad bladed screw driver Position the 11-8465 Rotor Holding Tool on
between the bottom of the cam and housing. Strike drive end of rotor shaft in the 4 o'clock po-
the screw driver handle with a sharp downward blow sition so any shaft deflection caused by
to "pop" the cam loose from taper of shaft. clamping action will be in a plane parallel
8.
Rotate cam until breaker contact cam follower to the breaker contacts.
is on high point of cam lobe. Adjust breaker points to
obtain a clearance of 0. 016±0. 003 inch. Tighten 4. Connect the timing light (Bendix Part No.
breaker contact securing screws to 20-25 Ib-in. 11-9110 or equivalent) black lead to any unpainted
9. Repeat steps 3 and 4.
surface of the magneto. Connect the red light lead
10. While holding rotating magnet in this EXACT
to the left breaker contact terminal and the green
location, rotate the breaker contact cam in the oppo-
light lead to the right breaker contact terminal.
site direction of rotation a few degrees BEYOND 5. Carefully adjust the LEFT breaker contacts
where the breaker contacts close, then rotate cam to just begin to open (light will go out) with the timing
in the normal direction of rotation until the breaker
pointer within the width of the L ("E" gap) mark.
contacts just begin to open. Point opening shall be 6.
Repeat step 5 for the RIGHT breaker contacts.
determined by the use of a timing light. (Bendix 7. Loosen the rotor holding tool and turn rotor
Part No. 11-9110 or equivalent. )
shaft in normal direction of rotation until cam follow-
11.
While holding cam in this EXACT position. ers of contact assemblies are on the high point of cam
push cam on magnet shaft as far as possible with the lobes. Contact point clearance should be 0.016±0.002
fingers. Tighten cam securing screw thereby draw- inch and 0.0160. 004 inch on LEFT and RIGHT con-
ing the cam down evenly and tightly. Torque cam tacts respectively. If dimensions do not fall within
securing screw to 16-20 lb-in. limits, readjust contact points and recheck to be sure
the points just begin to open when the timing pointer
is within the width of the L ("E" gap) mark.
11-22 Change 2