Wacker Neuson WM 90 Repair Manual page 101

WM 90 Repair
12.2.5 Engine Stops:
12.2.5.1 Fuel tank empty. Water, dirt, gum, etc. in gasoline.
12.2.5.2 Vapor lock. Gasoline evaporating in the fuel lines due to overheating
12.2.5.3 Vapor lock in the fuel lines or carburetor due to using too volatile gas
12.2.5.4 Air vent hole in the fuel tank cap plugged.
12.2.5.5 Bearing parts seized due to lack of lubrication.
12.2.5.6 Magneto or ignition coil faulty.
12.2.6 Engine Overheats:
12.2.6.1 Crankcase oil level low. Add oil immediately.
12.2.6.2 Spark timing incorrect.
12.2.6.3 Low-grade gasoline being used or engine is overloaded.
12.2.6.4 Cooling air circulation restricted.
12.2.6.5 Cooling air path misdirected causing loss of cooling efficiency.
12.2.6.6 Cylinder head cooling fins clogged with dirt.
12.2.6.7 Engine being operated in an enclosed space without sufficient cooling
12.2.6.8 Exhaust gas discharge restricted, or carbon deposits in the
12.2.6.9 Engine running on low-octane gasoline detonates due to heavy load at
12.2.7 Engine Knocks:
12.2.7.1 Poor quality gasoline.
12.2.7.2 Engine operating under heavy load at low speed.
12.2.7.3 Carbon or lead deposits in the cylinder head.
12.2.7.4 Spark timing incorrect.
12.2.7.5 Loose connecting rod bearing due to wear.
12.2.7.6 Loose piston pin due to wear.
12.2.8 Engine Backfires Through Carburetor:
12.2.8.1 Water or dirt in gasoline, or low grade gasoline.
12.2.8.2 Intake valve stuck.
12.2.8.3 Valves overheated or hot carbon particles in the combustion chamber.
12.2.8.4 Engine cold.
wc_tx000393gb.fm
of the engine.
blend (winter formula) in the hot season.
air.
combustion chamber.
low speed.
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Troubleshooting