Textron JACOBSEN GP400, Technical/Repair Manual

Page: 276 / 354

8-4 4252490-Rev A
CUTTING UNITS
8
Troubleshooting
Quality-of-Cut Troubleshooting
Factors That Affect Cut Appearance
Even though the cutting units are properly sharpened
and adjusted, some mowing practices and turf conditions
can cause poor cutting results. These include:
• Repetitious mowing patterns—tires running over the
same path—may cause depressions and ruts. This is
also known as compaction.
• Mowing with excessive moisture in the ground may
result in varying cutting heights. The mower slides
over the wet turf, leaving grass uncut and depressed.
• Repetitious cutting of grass in the same direction
may cause the grass to take a permanent set in that
direction. The reel and bedknife have difficulty
“lifting” the grass into cutting position. This condition
is called graining.
• Poor quality grass that is matted cannot be lifted and
cut uniformly.
• Dry grass does not lubricate the blades and leads to
early dulling of the blades.
In most cases, information provided by the user/customer
will provide the basis for the repairs and adjustments that
may be required. However, it is recommended that a “test
cut” be performed to evaluate the mower’s performance
before beginning repairs or adjustments.
An area should be available where “test cuts” can be
made. This area should provide known and consistent
turf conditions to allow accurate evaluation of the
mower’s performance.
Before performing a “test cut” to diagnose cut
appearance and mower performance, verify the following
items to ensure an accurate “test cut”:
1. Mowing (Ground) Speed
2. Reel Bearing Condition and Pre-Load (End Play)
Adjustment
3. Reel and Bedknife Sharpness
4. Bedknife Alignment to Reel
5. Bedknife-to-Reel Contact
6. Height-of-Cut (HOC)
7. Bedknife Application (Correct Bedknife)
8. Roller and Roller Bearing Condition
9. Reel Speed
10. Frequency-of-Clip (FOC)
Another “test cut” should be performed after the
completion of the repairs and/or adjustments to verify the
mower’s performance.