STIHL FS 56 RC Wont Stay Running Without Choke

Carburetor Assembly

The engine requires the choke to stay running because the internal fuel metering circuits are obstructed by varnish or the fuel pump diaphragm has lost its elasticity. This prevents the carburetor from maintaining the stoichiometric ratio required for combustion when the choke plate is open. Replacing the assembly ensures that non-serviceable internal check valves and fine mesh screens are cleared.

SKU: 4144 120 0608

Fuel Pick-up Body (Filter)

A partially clogged fuel filter in the tank restricts the volume of fuel available to the carburetor's venturi. The engine can only pull enough fuel to fire when the high vacuum of the 'choke' position is applied. Under normal operating conditions, the restriction causes a lean-out and subsequent stall.

SKU: 0000 350 3502

Spark Arrestor Screen

Carbon deposits (coking) on the exhaust screen create excessive backpressure, which interferes with the 2-stroke scavenging process. This disruption prevents fresh air-fuel charges from entering the cylinder effectively unless the intake velocity is artificially modified by the choke setting.

SKU: 4144 141 9002