Manual Chain Brake Function; Throttle Trigger Lockout (Disassembly) - Husqvarna 50 Workshop Manual

While holding onto the rear handle, release your grip
around the front handle. The chain saw will swing down-
ward allowing the bar tip to contact the tree stump. When
the tip of the bar contacts the stump, the chain brake
should activate.

Manual Chain Brake Function

Place the saw on firm ground and start the engine. Hold
the handles with both hands and apply full throttle.
Activate the chain brake by turning your left wrist against
the hand guard. The saw chain should stop moving
immediately.
Throttle Trigger Lockout
Disassembly
Press out the pin.
On the 50 and 50 Special models, the throttle lockout
lever has a small tab midway on the left side. Insert a
small screwdriver between the lever and lever opening on
the left side so that the tab will clear the handle then
withdraw the lever out through the top.