THRUSH AIRCRAFT, INC – MODEL S2R-R1340
AIRCRAFT MAINTENANCE MANUAL
4-8
Effective: 01/01/2008
F. Move the slide pointer up to align
with the 25 degree mark on the
scale.
G. Turn the propeller shaft in the normal
direction of rotation until the pivot
arm just contacts the slide. At this
point the lower light on the indicator
should flash on. The No. 1 piston is
now positioned at 25 degrees BTC.
H. Mount the magneto on the engine
without installing the rubber coupling.
Measure the distance between the
magneto drive shaft and the
magneto shaft couplings. Verify that
the two shafts are at their maximum
distance apart.
*NOTE*
Rubber couplings are
furnished in 1/32 inch
oversize, identified by
"B+1/32-inch" molded on the
face. The rubber coupling
used should be 0.020 to 0.030
inch less in thickness than
the distance between the two
metal couplings.
I. Remove the magneto from the
engine. With the straightedge in
exact alignment and with the rubber
coupling in place, rest the magneto
on the magneto mounting pad. Hold
the magneto in place and rotate the
rubber coupling between the two
metal couplings until the rubber
coupling can be engaged with the
metal couplings without causing the
magneto shaft to turn.
J. Fit the magneto over the dowel pins
on the mounting pad, and install the
magneto retaining bolts. Install the
distributor blocks, the distributor
cover halves and tighten the knurled
coupling.
K. After installation of magnetos, timing
and synchronizing check should be
performed.
IGNITION CONDUIT LEAD
REPLACEMENT
Ignition leads showing evidence of
chafing or deterioration of insulation
should be replaced. Replacement of
ignition leads may be accomplished as
follows:
A. Remove the magneto flexible conduit
to the distributor block cover elbow,
the elbow from the distributor block
cover, the distributor block cover
halves, and lift the distributor blocks
from the magneto.
B. Remove the connector at the spark
plug end of the lead, and the spark
plug conduit from the ignition cable
assembly. Loosen the coupling nut
on the conduit and slide the conduit
towards the rear. Remove the lead
from the distributor block.
C. Determine in which direction the lead
will pull the easiest, then splice and
solder the new lead onto the
opposite end of the old lead.
D. Dust the new lead with talc or
soapstone, and push the new lead
through as the old lead is pulled out.
When the new lead is through far
enough, cut it off the proper length.
E. Remove 1/2" of insulation from the
distributor block end. Separate the
strands and bend them back along
the insulation. Mark a new copper
ferrule with the proper number, then
install the ferrule and secure it with a
crimping tool.
F. Place the lead in the distributor
block, and secure it with the piercing
screw. Push the wire through the
spark plug conduit, and secure the
conduit to the manifold.
G. Remove 1/8 inch of insulation from
the lead. The insulation must bear
firmly against the brass disc inside
the spark plug connector. Treat the
ends of the insulation with an
insulating lacquer. After the lacquer
has dried, slide the connector into
