Husqvarna PT-26D Operator's Manual page 130

Trouble Shooting Guide
Problem
The engine runs erratically
128
Cause
• Air in fuel system
• Defective excess flow valve
• Blocked fuel filter
• Low feed pressure
• Clogged air filter
• Blocked fuel tank ventilation
• Disconnected fuel line (diffuser jet)
• Defective injector
• Defective injection pump
• Defective feed pump
• Incorrect fuel type
• Serious engine damage