Ryobi PCN 4040 Owner's Operation Manual page 18

MAINTENANCE
4. Remove the bar mounting nuts (B) using a
combination wrench (C) or a 5/8 in. spanner.
5. Remove the clutch cover (D), and the outer guide bar
plate (E).
6. Lay out the saw chain in a loop and straighten any kinks.
The cutters (F) should face in the direction of chain
rotation (G). If they face backwards, turn the loop over.
7. Place the chain drive links (H) into the bar groove (I).
8. Position the chain so there is a loop at the back
of the bar.
9. Hold the chain in position on the bar and place the
loop round the sprocket (J).
10. Fit the bar flush against the mounting surface so that
the bar studs (K) are in the long slot of the bar.
NOTE: When placing the bar on the bar studs ensure
that the adjusting pin (L) is in the chain tension pin hole.
11. Replace the outer guide bar plate ensuring that the
bar pin groove is at the bottom with the upper and
lower edges angled away from the guide bar.
12. Replace the clutch cover and bar mounting nuts.
13. Tighten the bar mounting nuts finger tight only.
The bar must be free to move for tension adjustment
14. Remove all slack from the chain by turning the chain
tensioning screw (M) clockwise until the chain
seats snugly against the bar with the drive links in the
bar groove.
15. Lift the tip of the guide bar up to check for sagging (N).
16. Release the tip of the guide bar and turn the chain
tensioning screw 1/2 turn clockwise. Repeat this
process until sagging does not exist.
17. Hold the tip of the guide bar up and tighten the bar
mounting nuts (O) securely.
The chain is correctly tensioned when there is no sagging
on the underside of the guide bar, the chain is snug,
but can be turned by hand without binding. Ensure that
the chain brake is not set.
NOTE: If chain is too tight, it will not rotate. Loosen the
bar nuts slightly and turn the tension adjuster 1/4 turn
anticlockwise. Lift the tip of the guide bar up and
retighten the bar nuts securely. Ensure that the chain will
rotate without binding.
ADJUSTING THE CHAIN TENSION (Fig. 48, 49
& 50)
WARNING
Never touch or adjust the chain while the motor
is running. The saw chain is very sharp. Always
wear protective gloves when performing
maintenance on the chain.
English
1 Stop the engine before setting the chain tension.
2. Make sure the guide bar nuts are loosened to
finger tight and turn the chain tensioner clockwise to
tension the chain.
NOTE: A cold chain is correctly tensioned when there
is no slack on the underside of the guide bar, the chain
is snug and it can be turned by hand without binding.
3. Retension the chain whenever the flats on the drive
links (A) hang out of the bar groove.
NOTE: During normal saw operation, the temperature
of the chain increases. The drive links of a correctly
tensioned warm chain (B) will hang approximately
1.25 mm (0.05 in.) out of the bar groove. To help
determine the correct warm chain tension, the tip of
the combination wrench (C) can be used as a guide.
NOTE: New chain tends to stretch. Check the chain
tension frequently and tension as required.
CAUTION
A chain tensioned while warm may be too tight
upon cooling. Check the "cold tension" before
next use.
CHAIN MAINTENANCE (Fig. 51 & 52)
CAUTION
Check that the switch is in the STOP "
position before you work on the saw.
Use only a low-kick-back chain on this saw. This fast-
cutting chain provides kick-back reduction when properly
maintained.
For smooth and fast cutting, maintain the chain properly.
The chain requires sharpening when the wood chips are
small and powdery, the chain must be forced through the
wood during cutting, or the chain cuts to one side. During
maintenance of the chain, consider the following:
Improper filing angle of the side plate can increase
I
the risk of a severe kick-back.
Raker (depth gauge) clearance (A).
I
1. Too low increases the potential for kick-back.
2. Not low enough decreases cutting ability.
If the cutter teeth hit hard objects such as nails and
I
stones, or are abraded by mud or sand on the wood,
have the Ryobi service dealer sharpen the chain.
NOTE: Inspect the drive sprocket for wear or damage
when replacing the chain (B). If signs of wear or
damage are present in the areas indicated, have the
drive sprocket replaced by a Ryobi service dealer.
11
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