Makita RBC420, Original Instruction Manual

Page: 19 / 172

19
Nylon cutting head
The nylon cutting head is a dual string trimmer head capable of both automatic and
bump & feed mechanisms.
The nylon cutting head will automatically feed out the proper length of nylon cord by
the changes in centrifugal force caused by increasing or decreasing rpms. However,
to cut soft grass more efficiently, bump the nylon cutting head against the ground to
feed out extra cord as indicated under operation section.
Operation
- Increase the nylon cutting head speed to approx. 6,000 rpm. Low speed (under
4,800 rpm) is not suitable, the nylon cord will not feed out properly at low speed.
- The most effective cutting area is shown by the shaded area.
If the nylon cord does not feed out automatically, proceed as follows:
1.
Release the throttle lever to run the engine idle and then squeeze the throttle
lever fully. Repeat this procedure until the nylon cord feeds out to the proper
length.
2. If the nylon cord is too short to feed out automatically with the above procedure,
bump the knob of the nylon cutting head against the ground to feed out the
nylon cord.
3. If the nylon cord does not feed out with procedure 2, rewind/replace the nylon
cord by following the procedures described under “Replacing the nylon cord”.
Replacing the nylon cord
1. Put off cover from housing, pressing two cover locking tabs located oppositely
on side of the housing.
2. Take off tap knob and spool from the housing.
3. Put each one end of two cutting lines into each holes at inner most of the slot on
one of spool outer flanges. Put the lines into spool gutters through each slit on
the flanges.
Most effective cutting area
Idle speed
Full speed
Tap knob
Pull up
Cover
Locking Tab
Housing Window
Tab knob
Spool
There is a hole inner
most of the slit.
Slit