Sears 358.356090-3.7/20" Chainsaw User Manual


 
E. CHAIN TENSION
COrrect chain tension is very important:
--a loose chain will wear the bar and itself,
--a loose chain can jump off the bar while
you are cutting.
--a tight chain can damage the saw and/or
break,
Chain tension is correct when the chain:
--can be lifted about 1/8" from the Guide Bar
at a point near the middle of the bar, and
--will move freely around the bar.
The chain stretches during use, especially
when new. Check tension:
:-- each time the saw is used
w more frequently whenthe chain isnew
J as the chain warms upto normal operatingtem-
perature
The Bar Clamp Nuts must be slightly loose to
tension the chain correctly.
1. Hold the tip of the Guide Bar up and turn the
Adjusting Screw. just until the,chain does not
sag beneath the Guide Bar, Figureg.
'NOTE: Turn screw clockwise to tighten ten-
sion; Turn screw counterclockwise to loosen
tension .....
2. Check the tension by lifting the chain from
the Guide Bar at the center of the bar. Figure
' i0.
F'
U'XTURE:
Your chain saw is powered by a two-cycle
engine which requres a fuel mixture of regu-
_lar gasoline anda high quality engine oil spe-
cially made for 2-cycle, air-cooled engines.
The internal design of the 2-cycle engine re-
quires lubrication of moving parts. Lubrica-
tion is provided when you use the recom-
...... mended mixtureof gasoline and oil, .
Gasoline must be i clean and not over two
months old. After :a sl_ort period of itime,
3. Continue turning the Adjusting Screw until
the tension is correct. _ .
4, Hold the tip of the Guide Bar up and tighten
the Bar Clamp Nuts with the Scrench.
5, Recheck tension.
CHAIN CAN BE
LIFTED 1/8"" WHEN
TENSION IS
CORRECT.
TURN
TO LOOSEN
TENSION
TURN
TO TIGHTEN
TENSION
: gasoline ,begins to chemically 'break down
and will form compounds that can cause hard
starting and damage in 2-cycle engines.
; The correct measure of gasoline to oil is very
: important.
:_ --Too much oil in the mixture will =fou! the
........ Spark plug.
........... --Too little oil will cause the engine to over-
heat resulting in damage,
Mix the fuel thoroughly in a container since
gasoline and oil do not readilycombine. Do not
try to mix fuel directly in the fuel tank.
Figure 9
o
Figure 10
1. USE THE FOLLOWING FUEL MIXTURES:
2. DO NOT USE:
BIA Oil (Boating Institute of America)
--Does not have proper additives for air-
cooled, 2-cycle engines and could cause
damage.
AUTOMOTIVE OIL-
- Does not have proper additivesfor 2-cycle
engines and couldcause damage.
GASOLINE CONTAINING ALCOHOL-
(High Test, Premium or Gasohol)
Stiffens criticalcarburetor fuel metering ele-
ments and causes engine damage from
overheating.
Increases vaporlock.
m Attractswater causing corrosiondamage.