McCulloch MXC1640DK, MXC1640DH SAW Chain Tension Adjustment, Abc, Chain Brake Mechanical Test

Models: MXC1840DH MXC1640DH MXC1840D MXC1640D MXC1640DK

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3 - ASSEMBLY INSTRUCTIONS

3 - ASSEMBLY INSTRUCTIONS

NOTE: The saw chain may droop slightly on the lower part of bar. This is normal.

10.Turn the knob (J) COUNTERCLOCKWISE until the TANG (K) is to the end of its travel. (Fig. 3-3F)

11.Install the clutch cover making sure the tang is posi- tioned in the lower hole in the guide bar. Make sure the chain does not slip off of the bar.

12.Lock the screw (N) be tight, and follow step 13 to adjust the chain tension.

13.Turn the tension ring clockwise tight (M); pull the con- trol button by arrow direction (L) to turn tightly be clockwise then push the control button back. (Fig. 3- 3G)

NOTE: The guide bar retaining knob is installed only hand tight at this point because saw chain adjustment is required. Follow instructions in Section, Saw Chain Tension Adjustment.

3-4. SAW CHAIN TENSION ADJUSTMENT

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

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

WARNING

Always wear heavy duty gloves when handling saw chain or making saw chain adjustments.

TO ADJUST SAW CHAIN:

1.

Hold nose of guide bar up and turn adjustment chain

 

ring (A) CLOCKWISE to increase chain tension.

 

Turning chain ring (A) COUNTERCLOCKWISE will

 

decrease amount of tension on chain. Ensure the

 

chain fits snugly all the way around the guide bar. (Fig.

 

3-4A)

2.

After making adjustment, and while still holding nose

 

of bar in the uppermost position, tighten the bar

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

If saw chain is TOO LOOSE or TOO TIGHT, the sprocket, bar, chain, and crankshaft bearings will wear more rapidly. Study Figure 3-4B for information concerning correct cold tension (A), correct warm tension (B), and as a guide for when saw chain needs adjustment (C).

TO TEST CHAIN BRAKE®:

1.The CHAIN BRAKE® is DISENGAGED (chain can move) when BRAKE LEVER IS PULLED BACK AND LOCKED. Be sure the chain break latch is in the on position. (Figure 3-5A).

2.The CHAIN BRAKE® is ENGAGED (chain is stopped) when brake lever is in forward position and the chain brake latch is in the off position. You should not be able to move chain (Figure 3-5B).

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 an Authorized Service Center for repair.

J

K

3-3F

L

N

M

 

3-3G

 

retaining button (B) securely. Chain has proper ten-

sion when it has a snug fit all around and can be

pulled around by gloved hand. (Fig. 3-BA)

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 knob so it is finger tight. Decrease tension by turning the bar adjustment chain ring 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 chain ring CLOCKWISE.

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

A

B

3-4A

ABC

3-4B

3-5. CHAIN BRAKE® MECHANICAL TEST

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.

WARNING

The purpose of the CHAIN BRAKE® is to reduce the possi- bility 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.

ON

3-5A

OFF

3-5B

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McCulloch MXC1640DK, MXC1640DH SAW Chain Tension Adjustment, Abc, Chain Brake Mechanical Test, To Adjust SAW Chain