Cub Cadet MTD 90 Series - Manual (Page 58)

78/83/90 Series Horizontal Shaft Engines
52
Disassembly and rebuilding of the carburetor
1. Clamp-off the fuel line to prevent fuel spillage, then disconnect the fuel line from the carburetor.
2. Disconnect the primer hose.
3. Remove the carburetor by following the steps described in Chapter 3: Air Intake and Filter.
NOTE: An insulator separates the carburetor from the cylinder head.
• A bowl vent port is in a recessed passage on the end of the carburetor that faces the insulator.
• A second passage in the insulator supplements the passage on the carburetor.
• Gaskets separate the insulator from the cylinder head and the carburetor from the insulator.
• A port in the carburetor to insulator gasket ties the bowl vent passages together.
4. Check the vent passages. See Figure 4.25.
5. Check the gaskets and the insulator block.
6. Remove the bowl bolt using a 10mm wrench. See
Figure 4.27.
NOTE: From this point an assessment can be made
about the viability of rebuilding the carbure-
tor.
• If extensive corrosion is evident, replace the
carburetor.
• If varnish build-up is too extensive to clean,
replace the carburetor.
7. When inverted, the float should rest in a level posi-
tion. See Figure 4.26.
Figure 4.25
Bowl vent port
Bowl vent
channel
insulator block
gasket
Figure 4.26
Float
Float pin
Float valve
Fuel inlet