Cub Cadet MTD P71 Series - Manual (Page 53)

F UEL S YSTEM AND G OVERNOR
47
8. Remove the main jet by using a narrow-shank
straight blade screwdriver. See Figure 4.20.
NOTE: Fuel enters the central column through a port
about 1/2” (1cm) from the bottom, to help prevent
the ingress of any residue in the bottom of the
bowl.
NOTE: The orifice in the main jet meters fuel into the cen-
tral column.
NOTE: Air from the main jet emulsion port enters the cen-
tral column near the top, then gets bubbled
through the emulsion tube into the metered fuel
flow to promote atomization.
NOTE: The main jet secures the emulsion tube in the cen-
tral column of the carburetor. See Figure 4.21.
9. Clean the carburetor body in an ultrasonic cleaner.
NOTE: Traditional dips are not recommended.
10. Rinse thoroughly.
11. Dry the carburetor body using compressed air.
12. Reassembly the carburetor and install it by following
steps 1-8 in reverse order.
13. Start engine and check the idle RPM using a tachom-
eter.
NOTE: Idle speed: If applicable, is 1,800 RPM + 160 RPM,
set using throttle stop screw. See Figure 4.22.
• For mower applications, the idle speed is not nor-
mally critical because the operator is not provided
with a throttle control.
14. Check the top no load speed of the engine.
See Figure 4.22.
NOTE: The top no load speed will vary depending on the
application. The specification for it will be listed in
the manual for each application.
Figure 4.20
Main jet
Figure 4.21
Emulsion tube
Main jet
O-rings
Figure 4.22
Digital tachometer confirms safe
operating speed