Exmark NAVIGATOR Operator's Manual page 51

Problem
Engine overheats.
Mower pulls left or right (with levers fully
forward).
Machine does not drive.
Abnormal vibration.
Uneven cutting height.
Blades do not rotate.
Possible Cause
1. Engine load is excessive.
2. Oil level in the crankcase is low.
3. Cooling fins and air passages for the
engine are plugged.
1. Tracking needs adjustment.
2. Tire pressure in drive tires not correct.
3. Reverse indicator and speed control
linkage need adjustment.
1. Bypass valve is not closed tight.
2. Drive or pump belt is worn, loose or
broken.
3. Drive or pump belt is off a pulley.
4. Broken or missing idler spring.
5. Hydraulic fluid level is low or too hot.
1. Cutting blade(s) is/are bent or unbalanced.
2. Blade mounting bolt is loose.
3. Engine mounting bolts are loose.
4. Loose engine pulley, idler pulley, or blade
pulley.
5. Engine pulley is damaged.
6. Blade spindle is bent.
7. Belt is damaged.
1. Blade(s) not sharp.
2. Cutting blade(s) is/are bent.
3. Mower deck is not level.
4. Underside of mower is dirty.
5. Tire pressure in drive tires not correct.
6. Spacers are in wrong location.
7. Tips of adjacent blades are at an uneven
cutting height. Blades tips should be even
within 3/16 inch which is approximately
one blade thickness.
1. PTO belt is worn, loose, or broken.
2. PTO shaft is not connected.
3. PTO belt is off pulley.
51
Troubleshooting
Corrective Action
1. Reduce the ground speed.
2. Add oil to the crankcase.
3. Remove the obstructions from the
cooling fins and air passages.
1. Adjust the tracking.
2. Adjust tire pressure in the drive tires.
3. Adjust the reverse indicator and the speed
control linkage.
1. Tighten the bypass valve.
2. Change the belt.
3. Change the belt.
4. Replace the spring.
5. Add hydraulic fluid to reservoir or let it
cool down.
1. Install new cutting blade(s).
2. Tighten the blade mounting bolt.
3. Tighten the engine mounting bolts.
4. Tighten the appropriate pulley.
5. Contact an Authorized Service Dealer.
6. Contact an Authorized Service Dealer.
7. Install new belt.
1. Sharpen the blade(s).
2. Install new cutting blade(s).
3. Level mower deck from side-to-side and
front-to-rear.
4. Clean the underside of the mower.
5. Adjust tire pressure in the drive tires.
6. Position spacers under hairpins.
7. Replace blades, spindles and (or) check
for damage to mower deck.
1. Check belt tension or replace belt
2. Connect PTO shaft.
3. Check belt for damage. Install belt and
check adjusting shafts and belt guides for
correct position.