Jacobsen LF 3400 Manuel De Maintenance page 23

4.20 REEL BACKLAPPING ______________________________________________________
!
WARNING
To prevent severe injury, keep hands, feet and clothing
away from rotating reels.
Carbon monoxide in the exhaust fumes can be fatal
when inhaled, never operate the engine without proper
ventilation
Check the reel and bedknife to determine if backlapping or
grinding will restore the cutting edge.
If wear or damage is beyond the point where the cutting
edges can be corrected by the lapping process, they must
be reground.
To backlap:
1. Lower the reels to the ground, disengage all drives,
engage parking brake and stop engine.
2. Loosen locknut (D) at valve stem.
3. Open hood and place back-lap switch (B) to
REVERSE. Start the engine and set throttle to low idle
speed.
4. Set mower switch on instrument panel to REVERSE.
Reels will begin rotating.
5. Both the front and rear reel valves contain an
adjustable valve (C) to control the speed of the reels.
The front valve controls the front three reels. The back
valve controls the two rear reels. Turn valve counter-
clockwise to reduce reel speed. Repeat for both valves.
6. After the desired speed is set, disengage reels and
stop engine. Tighten nut (D) to lock adjustment in
place. Start engine and set mower switch to REVERSE
to begin backlapping.
7. Apply lapping compound, with a long handled brush,
along the entire length of the reel.
8. When the blades have been evenly honed, carefully
and thoroughly wash off the remaining mixture.
9. Repeat the entire process on the other reels.
10. After backlapping, turn mow switch OFF (center
position) and set backlap switch (B) for FORWARD
rotation.
Important: The speed control valves limit reverse speed
only. Once the desired backlapping speed has been set the
valves can remain in this position for normal mowing. If full
reverse speed is needed, for instance during operation of
vertical mowers, the valve can be fully closed (turn
clockwise).
All manuals and user guides at all-guides.com
MAINTENANCE
D
C
REAR REEL VALVE SHOWN,
REPEAT FOR FRONT VALVE
4
B
LF021
Figure 4E
LF022
Figure 4F
GB-23