Service Manual

CAUTION: To reduce poten-
tial accidents, never perform
an adjustment or maintenance proce-
dure while the engine is running. Pull
the high tension wire
off the spark plug
to prevent an accidental start.
AIR CLEANER
The air cleaner must be maintained properly to
ensure foreign materials cannot damage the
engine
or foul the carburetor. The air cleaner
element must be cleaned after every
50 hours of
engine operation, or more frequently
if the engine
is operated in dusty
or dirty conditions.
Lift the cover tabs securing the air cleaner cover
to the housing and remove the cover (Figure 2-1).
Clean the inside
of the cover and housing if it
is dirty.
Figure 2-1
If the air cleaner element is dirty remove it from
the housing
for cleaning. DO NOT ALLOW DIRT
TO ENTER BEHIND THE ELEMENT OR ENGINE
DAMAGE WILL RESULT. Wash the element in a
solution of liquid detergent and water. Squeeze
the element to remove the dirt. Do not twist the
element or the element may tear. Press the
element in a dry rag until it is completely dry.
Saturate the element with approximately five
teaspoons of SAE
30 oil and squeeze to distribute
the oil thoroughly.
The element must be dampened with oil to
function properly. Replace the element and install
the cover. Assure that the cover snaps in place
and is seated securely on the air cleaner housing.
IMPORTANT: DO NOT OPERATE THE ENGINE
WITHOUT AN
AIR CLEANER ELEMENT OR
EXTREME ENGINE WEAR AND DAMAGE WILL
RESULT.
SPARK PLUG
Many times an inspection of the spark plug can
determine whether the engine is functioning
properly. A spark plug which is functioning
normally will show slight electrode wear with
brown
or greyish tan deposits. Oil fouled and
black carbon fouled plugs are caused by a rich
carburetor mixture, weak spark, or improper
gasoline to oil mixture. Excessively worn elec-
trodes or a blistered insulator indicate spark plug
overheating. Look for incorrect ignition timing,
cooling fins clogged with debris, improper gaso-
line to oil mixture and dirty carburetor, any of
which may cause this trouble.
IMPORTANT:
A CRACKED, FOULED OR DIRTY
SPARK PLUG MUST BE REPLACED. DO NOT
TRODES. GRIT MAY EVENTUALLY RELEASE
AGE.
The recommended spark plus is an NGK-BPMRGA
or NGK-BPMR4A (Champion RCJ8Y). See Page 1-5.
The air gap between the electrodes should be set
at
.8 mm (.032 in) (Figure 2-2). Since the air gap
increases gradually through use, the spark plug
should be removed after every 25 hours of opera-
tion to check its condition. Clean the area around
the spark plug to prevent foreign material from
falling into the cylinder. Install the spark plug with
the metal gasket and tighten to 70-105 Kg-Cm
(80-1 20 in-lb).
SAND BLAST, SCRAPE OR CLEAN
THE ELEC-
FROM THE PLUG AND CAUSE ENGINE DAM-
(.032 in)
EXHAUST SYSTEM
One important part of the maintenance for all
two-cycle engines is the cleaning
or de-carboning
of the exhaust system. This is done to assure the
unobstructed flow of exhaust gases and carbon
particles from the combustion chamber.
A se-
verely carboned muffler, spark arrester screen or
exhaust port will cause poor starting and
low
power output. To de-carbon the exhaust system,
11-1