MAINTENANCE AND REPAIR INSTRUCTIONS

SAW CHAIN TENSION ADJUSTMENT

WARNING: Always use protective gloves

when handling the saw chain.

Proper tension of saw chain is extremely important and must be checked before starting, as well as during any cutting operation.

Taking the time to make needed adjustments to the saw chain will result in improved cutting performance and prolonged chain life.

To adjust the saw chain:

1.Loosen bar nut, hold nose of guide bar up and turn adjustment screw (D) CLOCKWISE to increase chain tension. Turning screw COUNTERCLOCKWISE will decrease amount of tension on chain. Ensure the chain fits snugly all the way around the guide bar (Fig. 22).

D

Fig. 22

2.After making adjustment, and while still holding nose of bar in the uppermost position, tighten the bar retaining nut securely. Chain has proper tension when it has a snug fit all around and can be pulled around by gloved hand.

NOTE: If chain is difficult to rotate on guide bar or if it binds, too much tension has been applied. This requires minor adjustment as follows:

A.Loosen the bar retaining nut so it is finger tight. Decrease tension by turning the bar adjustment screw COUNTERCLOCKWISE slowly. Move chain back and forth on bar. Continue to adjust until chain rotates freely, but fits snugly. Increase tension by turning bar adjustment screw CLOCKWISE.

B.When saw chain has proper tension, hold nose of bar in uppermost position and tighten the bar retaining nut securely.

A B C

Fig. 23

CAUTION: A new saw chain stretches, requiring

adjustment after as few as 5 cuts. This is normal with a new chain, and the interval between future adjustments will lengthen quickly.

CAUTION: saw chain is TOO LOOSE or TOO

TIGHT, the sprocket, bar, chain, and crankshaft bearings will wear more rapidly. Study Fig. 23 for information concerning correct cold tension (A), correct warm tension (B), and as a guide for when saw chain needs adjusdjtment (C).

CHAIN BRAKE MECHANICAL TEST

WARNING: The purpose of the Chain Brake® is to

reduce the possibility of injury due to kickback; however, it cannot provide the intended measure of protection if the saw is operated carelessly.

Always test the Chain Brake® before using your saw and periodically while on the job.

Your chain saw is equipped with a Chain Brake® that reduces possibility of injury due to kickback. The brake is activated if pressure is applied against brake lever when, as in the event of kickback, operator’s hand strikes the lever. When the brake is actuated, chain movement stops abruptly.

To Test the Chain Brake®:

1.The Chain Brake® is DISENGAGED (chain can move) when BRAKE LEVER IS PULLED BACK AND LOCKED (A, Fig. 24).

2.The Chain Brake® is ENGAGED (chain is stopped) when brake lever is in forward position. You should not be able to move chain (B, Fig. 24).

NOTE: The brake lever should snap into both positions. If strong resistance is felt, or lever does not move into either position, do not use your saw. Take it immediately to a Authorized Service Center for repair. Call 1-800-520-5520 for more information.

A

B

Fig. 24

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MTD 1842AVCC, 1642AVCC, 1425NAV manual SAW Chain Tension Adjustment, Chain Brake Mechanical Test