Toro 51643 Service Manual page 26

Carburetor Disassembly (cont'd)
2.
Remove the fuel pump by removing the
4
screws
with lock washers securing the pump cover then
lifting off the pump diaphragm and pump cover
gasket.
NOTE: The gasket and the diaphragm are
extremely thin and may stick together giving the
appearance of one piece. Remember that the
pump diaphragm seals against the pump cover
and that the gasket seals against the carburetor
body. See Figure 19.
3.
Figure 19
Remove the four screws with lock washers
securing the main diaphragm cover assembly to
the carburetor. Carefully lift off the main diaphragm
cover assembly.
NOTE: The main diaphragm assembly and the
main diaphragm packing are thin and may stick
together giving the appearance of one piece, not
two. Remember that the main diaphragm gasket
seals against the carburetor body. See Figure 20.
Figure 20
NOTE: Before removing inlet needle pieces,
inspect inlet needle arm height using a depth
micrometer. The correct height is
1.4
to 1.6 mm
(.055 to .062") See Figure 21.
INLET NEEDLE ARM HEIGHT
INLET NEEDLE
Figure 21
Remove the inlet needle pieces from the
carburetor by removing the inlet needle pin set
screw and carefully lifting out the inlet needle arm
with inlet needle pin, the inlet valve spring and the
inlet needle valve. See Figure 22.
INLET NEEDLE
ARM AND PIN
Figure 22
5. Remove the throttle adjusting screw, throttle
adjusting screw spring and the high speed mixture
screw. See Figure 23.
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