Toro 74939 Operator's Manual page 64

Problem
The engine loses power.
The engine overheats.
The mower pulls left or right (with levers
fully forward).
The machine does not drive.
There is abnormal vibration.
Mowing is resulting in uneven cutting
height.
The blades do not rotate.
Possible Cause
1. The engine load is excessive.
2. The air cleaner is dirty.
3. The oil level in the crankcase is low.
4. The cooling fins and air passages
above the engine are plugged.
5. The vent hole in the fuel cap is plugged.
6. There is dirt in the fuel filter.
7. There is dirt, water, or stale fuel is in
the fuel system.
1. The engine load is excessive.
2. The oil level in the crankcase is low.
3. The cooling fins and air passages
above the engine are plugged.
1. The tracking needs adjustment.
2. The tire pressure in the drive tires is
not correct.
1. The by pass valves is not closed tight.
2. The pump belt is worn, loose or broken.
3. The pump belt is off a pulley.
4. The idler sprint is broken or missing.
5. The hydraulic oil level is low or too hot.
1. The cutting blade(s) is/are bent or
unbalanced.
2. The blade mounting bolt is loose.
3. The engine mounting bolts are loose.
4. The engine pulley, idler pulley, or blade
pulley is loose.
5. The engine pulley is damaged.
6. The blade spindle is bent.
7. The motor mount is loose or worn.
1. The blade(s) not sharp.
2. The cutting blade(s) is/are bent.
3. The mower deck is not level.
4. The underside of mower is dirty.
5. The tire pressure is not correct.
6. The blade spindle bent.
1. The mower deck belt is worn, loose or
broken.
2. The mower deck belt is off pulley.
3. The pump drive belt is worn, loose or
broken.
4. The idler spring is broken or missing.
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Corrective Action
1. Reduce the ground speed.
2. Clean the air cleaner element.
3. Add oil to the crankcase.
4. Remove the obstruction from the
cooling fins and air passages.
5. Clean or replace the fuel cap.
6. Replace the fuel filter.
7. Contact an Authorized Service Dealer.
1. Reduce the ground speed.
2. Add oil to the crankcase.
3. Remove the obstruction from the
cooling fins and air passages.
1. Adjust the tracking.
2. Adjust the tire pressure in the drive
tires.
1. Tighten the by pass valves.
2. Change the belt.
3. Change the belt.
4. Replace the spring.
5. Add hydraulic oil to reservoirs 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. Contact an Authorized Service Dealer.
1. Sharpen the blade(s).
2. Install new cutting blade(s).
3. Level the mower deck from side-to-side
and front-to-rear.
4. Clean the underside of the mower.
5. Adjust the tire pressure.
6. Contact an Authorized Service Dealer.
1. Install a new deck belt.
2. Install the mower deck pulley and
check the idler pulley, idler arm, and
spring for correct position and function.
3. Check the belt tension or install a new
belt.
4. Replace the spring.