Engine Will Not Start Or Is Hard To Start

· Motion control levers not in the "neutral lock" position.

· Park brake lever not in the proper position.

· Operator on seat.

· Key switch not in proper position.

· PTO engaged.

· Stale or improper fuel/fuel level

· Plugged fuel filter.

· Plugged air intake filter.

· Spark plug wire is loose or disconnected.

· Spark plug wire is not gapped correctly.

· Blown main fuse.

· Blown fuel injection system fuse (797 only)

· Electrical problem - dead battery.

· Choke adjusted incorrectly (777 only). See your John Deere dealer.

· Fuel injection system problems (797 only). See your John Deere dealer.

Engine Will Not Slow Idle

· Carburetion problems (777 only). See your John Deere dealer.

· Fuel injection system problems (797 only). See your John Deere dealer.

· Damaged or misadjusted throttle cable. See your John Deere dealer.

Engine Runs Rough or Stalls

· Plugged fuel filter.

· Plugged air intake system.

· Fuel cap vent dirty.

· Stale or improper fuel/fuel level.

· Spark plug worn or not gapped correctly.

· Fuel injection system problems (797 only). See your John Deere dealer.

· Choke adjusted incorrectly (777 only). See your John Deere dealer.

Engine Knocks

· Engine oil level low.

· Reduce load. (Slower ground speed.)

· Fuel is bad. Fill tank with fresh fuel, correct octane.

· Idle speed too slow.

Engine Overheats

· Low engine coolant.

· Radiator intake screens are dirty.

· Blocked radiator cooling fins.

· Low oil level.

· Do not operate at slow idle. Operate at fast idle.

· Plugged carburetor/throttle body air intake filter.

· Operating at too fast ground speed for conditions.

Engine Lacks Power

· Reduce load.

· Plugged carburetor/throttle body air intake filter.

· Plugged fuel filter.

· Improper type of fuel. Drain tank and fill with correct fuel.

· Clean radiator and screens to help prevent overheating.

· Dirty or improper spark plugs.

· Fuel injection system problems (797 only). See your John Deere dealer.

Engine Uses Too Much Oil

· Find and correct oil leaks.

· Incorrect engine oil.

· Plugged oil filter.

· Plugged air intake filter.

· Worn internal engine components. See your John Deere dealer.

Engine Backfires Through Carburetor/Throttle Body

· Carburetion or Fuel Injection System problems. See your John Deere dealer.

Engine Backfires Through Muffler

· Throttle should be at half fast position or higher when turning engine off.

High Fuel Consumption

· Improper type of fuel.

· Plugged air intake system.

· Operating at too fast ground speed for conditions.

· Improper valve clearance. See your John Deere dealer.

· Restricted air intake system.

Starter Will Not Work

· Blown main fuse.

· Loose or corroded battery or ground connections.

· Neutral start switches faulty or not adjusted properly. See your John Deere dealer.

· Key switch or starter faulty. See your John Deere dealer.

· PTO engaged.

· Motion control levers and park brake lever not in proper position.

· Operator not on seat.

Battery Will Not Charge

· Loose or corroded connections.

PTO Switch Does Not Work

· Poor connection between harness and clutch.

· Blown main fuse

· Bad switch.

Starter Turns Slowly

· Loose or corroded battery or ground connections.

· Low battery power - charge battery.

· Engine oil viscosity too heavy.

Excessive Machine Vibration

· Engine speed too slow.

Machine Will Not Move With Engine Running

· Park brake locked.

· Transmission oil level low.

· Transmission oil cold - allow engine to warm.

· Pump drive belt slipping or broken.

· Free-wheeling pump release valve engaged.

· Transmission problems. See your John Deere dealer.

Machine Creeps With Engine Running and Motion Control Levers in a Neutral Position

· Needs control linkage adjustment.

· Needs transmission neutral adjustment.

· Engine speed too slow.

Brakes Not Working Correctly

· Brakes out of adjustment - adjust linkage.

· Brake bands wet.

· Worn brake bands.

Steering Not Working

· Free-wheeling pump release valve partially engaged.

· Needs control linkage adjustment.

· Improper tire inflation.

· Hydrostatic transmission oil low.

Discharge Chute Plugged

· Grass is wet - mow grass only when dry.

· Raise cutting height.

· Mow at full fast throttle.

· Ground speed too fast for conditions.

· Correct installation of deck drive belt.

Mower Deck Vibrates

· Run engine at fast throttle.

· Loose hardware.

· Check/replace deck drive belt.

· Blade bolts are loose.

· Blades are bent or worn.

· Sharpen and balance blades.

· Remove belt shields and clean debris from sheaves.

· Check sheaves for proper alignment or damage. See a John Deere dealer.

Mower Blades Do Not Engage

· Deck drive belt slipping or broken.

· Mule drive belt slipping or broken.

· Deck or mule belt tension spring not installed or broken.

· PTO switch failure.

· Main fuse is blown.

· Loose electrical connections.

Mower Mows Unevenly

· Mower deck not properly leveled.

· Ground speed too fast for conditions.

· Run engine at fast throttle.

· Reduce ground speed when making turns.

· Sharpen or replace blades.

· Change mowing pattern.

· Check air pressure in all traction unit tires.