Overheating

1. Firing incorrect
   

• Spark plug dirty, broken, or maladjusted
  

  
  

• Spark plug incorrect
  

  
  

• IC igniter trouble
  

  
  

   

   

1. Fuel/air mixture incorrect
   

• Air jet clogged or wrong size
  

  
  

• Fuel level in carburettor float bowl too low
  

  
  

• Carburettor holder loose
  

  
  

• Air cleaner poorly sealed or missing
  

  
  

• Air cleaner clogged
  

  
  

   

1. Compression high
   

• Carbon built up in combustion chamber
  

  
  

   

1. Engine load faulty
   

• Clutch slipping
  

  
  

• Engine oil level too high
  

• Engine oil viscosity too high
  

• Drive train trouble
  

  
  

• Brake dragging
  

  
  

   

1. Lubrication inadequate
   

• Engine oil level too low
  

  
  

• Engine oil poor quality or incorrect
  

  
  

   

1. Coolant incorrect
   

• Coolant level too low
  

  
  

• Coolant deterioted
  

  
  

   

1. Cooing system component incorrect
   

• Radiator clogged
  

  
  

• Thermostat trouble
  

  
  

• Radiator cap trouble
  

  
  

• Thermostatic fan switch trouble
  

  
  

• Fan relay trouble
  

  
  

• Fan motor broken
  

  
  

• Fan blade damaged
  

  
  

• Water pump not turning
  

  
  

• Water pump impeller damaged
  

  
  

   

1. Overcooling
   

• Cooling system component incorrect
  

  
  

   

1. Clutch operation faulty
   

• Friction plate worn or warped
  

  
  

• Steel plate worn or warped
  

  
  

• Clutch spring broken or weak
  

  
  

• Clutch hub or housing unevenly worn
  

  
  

   

1. Clutch not disengaging properly
   

• Clutch spring tension uneven
  

  
  

• Clutch housing frozen on drive shaft
  

  
  

   

   

   

• Clutch release mechanism trouble