Stihl RZ 900 Series Instruction Manual - Page 55

Problem: Mower will not raise. Cause Remedy Lift linkage not properly attached or See authorized STIHL servicing damaged. dealer. Problem: Engine stalls easily with mower engaged. Cause Remedy Engine speed to slow. Set to full throttle. Ground speed too fast. Decrease ground speed. Cutting height set too low. Increase the cutting height. Discharge chute jamming with cut grass. Cut grass with discharge pointing towards previously cut area. Problem: Excessive mower vibration. Cause Remedy Blade mounting bolts are loose. Tighten to 120 ft.lbs (163 Nm). Mower blades, arbors, or pulleys are Check and replace as necessary. bent. Mower blades are out of balance. Remove, sharpen, and balance blades. See Servicing the Mower Blades. Belt installed incorrectly. Install belt correctly. Problem: Excessive belt wear or breakage. Cause Remedy Bent or rough pulleys. Repair or replace. Using incorrect belt. Replace with correct belt. Incorrect belt tension. Adjust to correct tension. Problem: Drive belt slips or fails to drive. Cause Remedy Incorrect belt tension. Adjust to correct tension. Drive belt is broken. Replace with new belt. Problem: Mower does not engage. Cause Remedy Electrical wiring damage. Locate & repair damaged wire. Battery voltage too low. Charge battery and check alternator. See Battery Maintenance. Troubleshooting Common Cutting Problems Problem: Streaking Streaking is when thin strips of uncut grass are left behind the mower. Streaking is usually caused by operator error or poor blade maintenance. Problem: Streaking Not overlapping cutting rows enough. Overlap your cutting rows Not overlapping enough when turning. When turning your effective cutting width decreases-overlap more when turning. Problem: Scalping Scalping is when the mower deck comes close to or hits the ground. Scalping can be caused by the mower deck misadjustment, unevenness in the lawn, or by mower deck bouncing because the ground speed is too fast. Cause Lawn is uneven or bumpy. Mower deck cutting height is set too low. Ground speed is too fast. Deck is not leveled correctly. Tire pressure is low or uneven. Remedy Roll or level the lawn. Raise the cutting height. Slow down. Correctly level the deck. Check and inflate the tires. Problem: Stepped Cutting Stepped cutting is sharp ridges or uneven levels left in the lawn surface. Stepped cutting is usually caused by mower deck damage or misadjustment, or damage to the mower blades. Cause Deck is not leveled correctly. Tires are not properly inflated. Blades are damaged. Deck shell is damaged. Mower spindle is bent or loose. Blades are installed incorrectly. Remedy Level the deck correctly. Check and inflate the tires. Replace the blades. Repair or replace the deck. Repair or replace the spindle. Reinstall the blades correctly. Problem: Uneven Cutting Uneven cutting is waviness or smooth troughs in the lawn surface. Uneven cutting is usually caused by mower deck damage or misadjustment. Cause Blades are not sharp. Blades are worn down too far. Engine speed is too slow. Ground speed is too fast. Deck is plugged with grass. Remedy Sharpen your blades. Replace your blades. Always mow at full throttle. Slow down. Clean out the mower. Cause Remedy Deck is not leveled correctly. Level the deck correctly. Blades are dull or worn. Sharpen or replace the blades. Blades are damaged. Replace the blades. Deck is clogged with grass clippings. Clean out the deck. Deck shell is damaged. Repair or replace the deck. 55