TM 9-3431-254-14&P
Manufacturer's Instruction Bulletin in the back of
this manual.
PRE-CLEANER
IGNITION SYSTEM
The collector type pre-cleaner, mounted to the top of
the air cleaner as illustrated in Fig. B-8, removes the
A battery ignition system is standard equipment on
larger dirt and dust particles before the air reaches
this model of engine. The distributor is of the auto-
the main air cleaner.
matic advance type and it is driven off an engine
speed shaft through a pair of two to one ratio gears,
Clean bowl regularly of accumulated dust and dirt.
thus driving the distributor rotor at one half engine
Do not use oil or water in pre-cleaner, this must be
speed in a counter-clockwise direction when viewed
kept dry.
from above.
Daily attention to the air cleaner and pre-cleaner is
one of the most important considerations in prolong-
The running spark advance of the engine is 23 and
ing engine life.
the distributor is fully advanced at 2000 R.P.M.
Engine must be running at 2000 R.P.M. or over, when
GASOLINE STRAINER
checking or adjusting spark advance.
The gasoline strainer is very necessary to prevent
sediment, dirt and water from entering the carburetor
tion coil furnished are products of either the Delco-
and causing trouble or even complete stoppage of the
Remy Company or Prestolite Company It is suggested
engine. This strainer has a glass bowl and should be
that when replacement of any of these parts becomes
inspected frequently, and cleaned if dirt or water are
necessary, that the replaced parts be of the same
present.
manufacture as the other components.
swing wire bail to one side, see Fig. B-9. There will
TIMING
be less danger of breaking the gasket if the bowl is
given a twist as it is being removed. Clean bowl and
screen thoroughly. Replace gasket if it has become
FIRING ORDER
damaged or hardened. Repair kits are available for
The firing order of the cylinders is 1-3-4-2, and the
service replacement, refer to parts list in rear of
battery type distributor rotates at one-half engine
manual.
speed, as is the case with conventional 'in line' en-
gines. The intervals between the firing of the cylin-
CARBURETOR ADJUSTMENT
ders is 180. No. 1 cylinder is the one nearest to the
The main metering jet in the carburetor is of the fix-
flywheel in the left bank of cylinders, when viewed
ed type, that is, it requires no adjustment. The idle
from the flywheel end of the engine. No. 3 cylinder is
needle should be adjusted for best low speed opera-
the other cylinder in this bank. No. 2 cylinder is the
tion, while carburetor throttle is closed by hand. For
one nearest to the flywheel in the right bank of cylin-
illustrations and more information, see Carburetor
ders and No. 4 is the other cylinder in this bank. The
