McCulloch M4620 - SPARK PLUG REPLACEMENT; CHAIN SHARPENING; Required Tools; Sharpening Procedure

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SPARK PLUG
The spark plug should be replaced each
year to ensure the engine starts easier and
runs better. Ignition timing is fixed and non-
adjustable.
1. Loosen 3 screws on cylinder cover.
2. Remove the cylinder cover.
3. Pull off the spark plug boot.
4. Remove spark plug from cylinder and
discard.
5. Replace with Champion RCJ--7Y spark
plug and tighten securely with a 19 mm
socket wrench. Spark plug gap should
be 0,5 mm.
6. Reinstall the spark plug boot.
7. Reinstall the cylinder cover and 3
screws. Tighten securely.
Spark Plug
CHAIN SHARPENING
WARNING: Improper chain sharpen-
ing techniques and/or depth gauge mainte-
nance will increase the chance of kickback
which can result in serious injury.
WARNING: Wear protective gloves
when handling chain. The chain is sharp and
can cut you even when it is not moving.
Conditions which indicate the need for chain
sharpening:
S Reduction in size of wood chips. The size
of the wood chip will decrease as thechain
gets duller until it becomes more like a
powder than a chip. Note that dead or
rotted wood will not produce a good chip.
S Saw cuts to one side or at an angle.
S Saw has to be forced through the cut.
Tools required:
S 3/16 inch (4,5 mm) diameter round file and
file holder
S Flat file
S Depth gauge tool
TO SHARPEN CHAIN:
1. Move ON/STOP switch to the STOP
position.
2. Check chain for proper tension. Adjust
chain tension if necessary.
3. Sharpen cutters.
S To sharpen the cutters, position the
file holder level (90° ) so that it rests
on the top edges of the cutter and
depth gauge.
NOTE: The chain has both left and
right hand cutters.
Depth Gauge
File
File Holder
Cutter
90°
S Align the 25° file holder marks paral-
lelwith thebar andto the center ofthe
chain.
Cutter
Cutter
25°
File Holder Line
S Sharpen cutters on one side of the
chain first. File from the inside of each
cutter to the outside. Then, turn the
chain saw around and repeat the pro-
cess for the other side of the chain.
S File on the forward stroke only. Use 2
or 3 strokes per cutting edge.
S Keep all cutters the same length
when filing.
S File enough to remove any damage
to cutting edges (side plate and top
plate of cutter).
A
ll Cutters
Same Length
Remove Damage
Top Plate
Side Plate
S File chain to meet the specifications
as shown.
25°
60°
60°
Rounded
Corner
0,65 mm
Right
Hook Angle
Wrong
Squared O
f
f
Corner
Too Much Hook
A
ngle
WARNING: Maintain the proper hook
angle according to the manufacturer’s specifi-
cations for the chain you are using. Improper
hook angle will increase the chance of kick-
back which can result in serious injury.