Operating instructions – Ryobi 790r User Manual
Page 13
13
HOLDING THE TRIMMER
Before operating the unit, stand in the operating position
(Fig. 19). Check for the following:
• The operator is wearing eye protection and proper
clothing
• With a slightly-bent right arm, the operator’s right hand
is holding the shaft grip
• The operator’s left arm is straight, the left hand holding
the J-handle
• The unit is at waist level
• The cutting attachment is parallel to the ground and
easily contacts the grass without the need to bend over
Once you are in the operating position, hook the
shoulder strap to the unit.
WARNING:
Always wear eye, hearing, foot
and body protection to reduce the risk of
injury when operating this unit.
OPERATING INSTRUCTIONS
Fig. 19
ADJUSTING TRIMMING LINE LENGTH
The Bump Head™ cutting attachment allows you to
release trimming line without stopping the engine. To
release more line, lightly tap the cutting attachment on the
ground (Fig. 20) while operating the trimmer at high speed.
NOTE: Always keep the trimming line fully extended.
Line release becomes more difficult as the cutting
line becomes shorter.
Fig. 20
Each time the head is bumped, about 1 inch (25.4 mm) of
trimming line is released. A blade in the cutting
attachment shield will cut the line to the proper length if
excess line is released.
For best results, tap the Bump Head™ on bare ground or
hard soil. If line release is attempted in tall grass, the
engine may stall. Always keep the trimming line fully
extended. Line release becomes more difficult as the
cutting line becomes shorter.
NOTE: Do not rest the Bump Head™ on the ground
while the unit is running.
Some line breakage will occur from:
• Entanglement with foreign matter
• Normal line fatigue
• Attempting to cut thick, stalky weeds
• Forcing the line into objects such as walls or fence posts
TIPS FOR BEST TRIMMING RESULTS
• For best trimming results, operate unit at full throttle.
• Keep the cutting attachment parallel to the ground.
• Do not force the cutting attachment. Allow the tip of
the line to do the cutting, especially along walls.
Cutting with more than the tip will reduce cutting
efficiency and may overload the engine.
• Cut grass over 8 inches (200 mm) by working from top
to bottom in small increments to avoid premature line
wear or engine drag.
• Cut from left to right whenever possible. Cutting to the
right improves the unit's cutting efficiency. Clippings
are thrown away from the operator.
• Slowly move the trimmer into and out of the cutting
area at the desired height. Move either in a forward-
backward or side-to-side motion. Cutting shorter
lengths produces the best results.
• Trim only when grass and weeds are dry.
• The life of your cutting line is dependent upon:
• Following the previously-explained trimming techniques
• What vegetation is cut
• Where vegetation is cut
For example, the line will wear faster when trimming against
a foundation wall as opposed to trimming around a tree.
CAUTION: Do not remove or alter the line
cutting blade assembly. Excessive line length
will make the clutch overheat. This may lead to
serious personal injury or damage to the unit.