We sell only genuine Cub Cadet ® parts.
Enter Your Model Number
The Bumper Head Knob is the part of the trimmer that when struck on the ground, advances the trimmer line in the spool.
To remove the Bumper Head Knob, thread it off the spindle of the gear box assembly.
The pipe is in the form of a Venturi: it narrows in section and then widens again, causing the airflow to increase in speed in the narrowest part.
Below the Venturi is a butterfly valve called the throttle valve — a rotating disc that can be turned end-on to the airflow, so as to hardly restrict the flow at all, or can be rotated so that it (almost) completely blocks the flow of air.
This valve controls the flow of air through the carburetor throat and thus the quantity of air/fuel mixture the system will deliver, thereby regulating engine power and speed. The throttle is connected, usually through a cable or a mechanical linkage of rods and joints.
Fuel is introduced into the air stream through small holes at the narrowest part of the Venturi and at other places where pressure will be lowered when not running on full throttle.
The purpose of the 738-04124A Shear Pin is to protect your snowblower.
If the auger gets jammed or clogged, the Shear Pin is designed to snap at a certain point of pressure, so it will not damage any other part of the unit.