shroud and secure with the five lock-
(4) Position the rear shroud cover (12) on
washers (10) and screws (8).
the lower shroud and heat deflector
and secure with the lockwasher (10),
(6) Install the spark plugs and ignition
screw (8), 2 lockwashers (14) and 2
cables (par, 114).
(7) Install the remaining shrouds and heat
(5) Place the cylinder head shroud (7) on
deflector in a similar manner.
the installed shroud cover and lower
Section III. MANIFOLD AND CYLINDER BLOCK GROUP
Replace a fitting damaged beyond re-
The manifold and cylinder block group, con-
(4) Inspect all attaching parts for distor-
sisting of the carburetor, intake and exhaust
tion and damaged threads. Replace
manifold, cylinder heads, cylinder block assem-
all defective parts,
blies, and the muffler, make up the upper por-
tion of the engine where mixing and combus-
tion of the fuel takes place. The carburetor
(1) Install the elbow (14, fig. 24), pipe
meters fuel into the air stream passing into the
nipple (13), and coupling (12) in the
manifold. The intake valves of the cylinder
intake and exhaust manifold (24).
block assemblies admit the air-fuel mixture into
(2) Install the muffler (7) in the coupling
their respective cylinders at the precise time for
(12) and secure the muffler to the
compression and combustion. The burnt gases
muffler mount (11) with the clamp
pass out of the cylinder through the exhaust
(8), two lockwashers (9), and hex
valves, manifold, and muffler.
(3) Install the elbow (6) on the muffler.
(4) Install the two pipe nipples (1 and 4,
fig. 8) and the elbow (3).
(1) Remove the two pipe nipples (1 and 4,
fig. 8) and elbow (3).
(2) Remove the elbow (6, fig. 24) from
the muffler (7).
(1) Start the engine (par. 41) and allow
(3) Remove the two hex nuts (10), lock-
the engine to warm up properly be-
washers (9), and the clamp (8) that
fore making any adjustments on the
secure the muffler to the muffler mount
(11) and unscrew the muffler from
(2) Close the throttle and adjust the throt-
the coupling (12).
tle stop screw (14, fig. 25) for the
(4) Remove the coupling, pipe nipple (13),
desired idle speed.
and elbow (14) from the intake and
(3) Turn the idle adjusting needle (20)
exhaust manifold (24).
counterclockwise until the engine rolls
b. Cleaning, Inspection, and Repair.
because of a rich mixture.
(1) Clean rust and corrosion from the
(4) Turn the needle clockwise until the
muffler and all fittings with a wire
engine runs irregularly because of a
(5) T u r n the needle counterclockwise
(2) Inspect the muffler for cracks, breaks,
again as far as possible maintaining
and damaged threads. Replace a de-
smooth engine operation.
Note. This adjustment will give a slower
(3) Inspect the various fittings for cracks,
idling speed than a slightly leaner adjust-
breaks, d i s t o r t i o n , and damaged
ment with the same throttle stop screw set-
threads. R e p a i r damaged threads.
ting, but will give the smoothest performance.