Service Manual

5.61
ENGINE
5
Low Compression
• No valve clearance
• Valve not seating properly (bent valve or carbon / debris
accumulated on sealing surface)
• Cylinder head gasket leak
• Cylinder or piston worn
• Piston rings worn, leaking, broken, or sticking
• Bent valve or stuck valve
• Valve spring broken or weak
• Rocker arm sticking
Backfiring
• Fouled spark plug or incorrect plug or plug gap
• Speed limiter system malfunction
• Exhaust system air leaks
• Ignition system faulty:
Spark plug cap cracked / broken
Ignition coil faulty
Ignition switch circuit faulty
Poor connections in ignition system
Ignition timing incorrect
Sheared flywheel key
• Valve sticking