Yard Machines MTD1425NAV Operator's Manual page 19

MAINTENANCE AND REPAIR INSTRUCTIONS
GUIDE BAR MAINTENANCE:
Most guide bar problems can be prevented merely by
keeping the chain saw well maintained.
Insufficient guide bar lubrication and operating the saw
with chain that is too tight will contribute to rapid bar wear.
To help minimize bar wear, the following guide bar
maintenance procedures are recommended.
BAR WEAR - Turn guide bar frequently at regular
intervals (for example, after 5 hours of use), to ensure
even wear on top and bottom of bar.
BAR GROOVES - Bar grooves (or rails which support and
carry the chain) should be cleaned if saw has been used
heavily or if saw chain appears dirty. Rails should always
be cleaned every time saw chain is removed.
OIL PASSAGES - Oil passages on the bar should be
cleaned to ensure proper lubrication of the bar and chain
during operation.
NOTE: The condition of the oil passages can be easily
checked. If the passages are clear, the chain will
automatically give off a spray of oil within
seconds of starting the saw. Your saw is
equipped with an automatic oiler system.
CHAIN MAINTENANCE
Chain Tension
Check the chain tension frequently and adjust as often as
necessary to keep the chain snug on the bar, but loose
enough to be pulled around by hand.
Breaking in a New Saw Chain
A new chain and bar will need chain readjustment after
as few as 5 cuts. This is normal during the break-in
period, and the interval between future adjustments will
begin to lengthen quickly.
WARNING:
removed from a loop of chain. This could
cause damage to the sprocket.
Chain Lubrication
Always make sure the automatic oiler system is working
properly. Keep the oil tank filled with Genuine Factory
Parts Chain, Bar and Sprocket Oil.
Adequate lubrication of the bar and chain during cutting
operations is essential to minimize friction with the guide bar.
Never starve the bar and chain of lubricating oil. Running
the saw dry or with too little oil will decrease cutting
efficiency, shorten saw chain life, cause rapid dulling of
chain, and lead to excessive wear of bar from
overheating. Too little oil is evidenced by smoke or bar
discoloration.
Chain Sharpening
Chain sharpening requires special tools to ensure that
cutters are sharpened at the correct angle and depth. For
the inexperienced chain saw user, we recommend that
the saw chain be professionally sharpened by the
nearest Authorized Service Center. If you feel
comfortable sharpening your own saw chain, special
tools are available from your Authorized Service Center.
Never have more
than 3 links
19
CHAIN REPLACEMENT INFORMATION
There may be other quality equivalent replacement
components for achieving kickback protection.
Bar Length Drive Links
14" Bar
16" Bar
18" Bar
INERTIA CHAIN BRAKE
NOTE: THIS SAW IS EQUIPPED WITH AN INERTIA
CHAIN BRAKE. IF THE SAW KICKS BACK
WHILE IN USE, THE INERTIA OF THE MOVING
SAW WILL ACTIVATE THE BRAKE. A BRAKE
BAND AROUND THE CLUTCH DRUM
ACTIVATES AND STOPS THE MOVING CHAIN.
CHAIN BRAKE ® OPERATIONAL TEST
Test the Chain Brake ® periodically to ensure proper
function.
Perform a Chain Brake ® test prior to initial cutting,
following extensive cutting, and definitely following any
Chain Brake ® service. Test the Chain Brake:
1. Place saw on a clear, firm, flat surface.
2. Start engine.
3. Grasp the rear handle (A) with your right hand (Fig. 33).
4. With your left hand, hold the front handle (B) [not
Chain Brake ® lever (C)] firmly (Fig. 33).
5. Squeeze the throttle trigger to 1/3 throttle, then
immediately activate the Chain Brake
WARNING:
deliberately. Keep the chain from touching
anything; don't let the saw tip forward.
6. Chain should stop abruptly. When it does,
immediately release the throttle trigger.
WARNING:
and take your unit to the nearest Authorized
Service Center for service.
7. If Chain Brake ® functions properly, turn the engine off
and return the Chain Brake
position.
A
Part Number
6220-210803
49 DL
6220-210816
54 DL
6220-210805
60 DL
® ACTION
® lever (C) (Fig. 33).
Activate the Chain
Brake ® slowly and
If chain does not
stop, turn engine off
® to the DISENGAGED
B
C
Fig. 33