Mulching, Cutting height adjustment, Handle height adjustment – Yard Machines 509 User Manual
Page 13: Engine adjustments

13
For a healthier lawn, never cut off more than one-third 
of the total length of the grass. Your lawn should be cut 
in the fall as long as there is growth. This mower is 
designed to be operated at full throttle to give you the 
best cut and do the most effective job of mowing or 
mulching.
WARNING: If you strike a foreign object,
stop the engine. Remove wire from the
spark plug, thoroughly inspect the mower
for any damage, and repair the damage
before restarting and operating the
mower. Extensive vibration of the mower
during operation is an indication of
damage. The unit should be promptly
inspected and repaired.
Mulching
For effective mulching, do not cut wet grass because it 
tends to stick to the underside of the deck, preventing 
proper mulching of grass clippings. New or thick grass 
may require a narrower cut. The ground speed should 
be adjusted to the condition of the lawn. If mowing has 
been delayed and the grass has been allowed to grow 
in excess of 4”, mulching is not recommended. Mow 
using the side discharge to reduce the grass height to 3 
1/4” maximum before mulching.
SECTION 7: MAKING ADJUSTMENTS
WARNING: Do not at any time make any
adjustments without first stopping engine
and disconnecting spark plug wire.
Cutting Height Adjustment
Figure 15
An adjusting plate and spring lever at each wheel 
position provides cutting height adjustment. Each 
adjusting plate has nine height positions. When the 
spring lever is moved from one location to another the 
height of cut will be changed. Simply depress the lever 
towards wheel and move lever assembly to desired 
position. See Figure 15.
IMPORTANT:
All wheels must be placed in the same
relative position. For rough or uneven lawns, move the 
height adjustment lever to a higher position. This will 
help stop scalping of the grass.
Handle Height Adjustment
Your mower is shipped with the handle in the higher 
height position. To lower the height proceed as follows:
•
Remove the starter rope from the rope guide.
•
Remove the upper handle by removing the hand 
knobs and carriage bolts. Lay the upper handle out 
of the way, being careful not to bend or kink the 
cables.
•
Remove the hairpin clips from the weld pins on the 
handle brackets. Press out on the legs of the lower 
handle. Remove lower handle from the mower.
•
Turn lower handle around so the notch on the 
bottom of the lower handle is facing forward. 
Reassemble, placing the bottom holes in the 
handle over the weld pins in the handle mounting 
bracket. See Figure 16.
•
Reassemble the upper handle to the lower handle.
•
Place the hairpin clips in the inner holes in the weld 
pins and attach the starter rope as instructed in the 
Assembly Section.
Figure 16
Engine Adjustments
See the separate engine manual packed with your unit 
for adjustments to the engine.
Height Adjustment
Lever
Notch
Lower Handle
