Full – Auto – Choke
Fast idle cam
Fast idle
adjusting screw
1. Remove air intake hose.
2. Make sure engine coolant temperature is below 10�C
(50�F).
3. Check operation of choke valve under various engine
conditions.
Engine condition
Choke valve operation
Before starting
Closed
Just after starting
Slightly opens
(Carburetor ID Mark TMB)
approx. 1.8 mm (.071 in.) clearance
Just after starting
Slightly opens
(Carburetor ID Mark TEB)
approx. 2.3 mm (.091 in.) clearance
During warm–up
Opens wider as engine coolant
temperature increases
After warming up
Fully open
(running at idle)
4. If choke valve does not operate properly, inspect and
adjust or replace the choke body assembly.
Workman 3000/4000 Series
Choke adjusting screw
Cam follower
Thermo–wax element
Figure 35
Choke valve
Page 3 – 25 Rev. B
Choke pinion
Choke lever
Figure 36
Liquid Cooled Gas Engine