TM 10-3930-653-14&P Fig. 4-130. d. When the carburetor throttle valve is full open. The  valve  is  nearly  the  fully  open  position  at  low engine speeds, but with the increase of engine rotation, it begins  to  close  before  the  rotation  reaches  the  speed corresponding to the rated output, and finally the valve is almost   totally   closed   when   the   rotation   of   the   engine attains near maximum no-load speed. Fig. 4-131. e. When load fluctuates. If   the   load   suddenly   increases   during   a   stable operation of the engine with the governor valve properly opened,  the  engine  speed  at  first  somewhat  decreases But this speed reduction lessens the pressure difference between  both  sides  of  the  governor  valve,  which  in  turn diminishes the sucking action on the stabilizer piston and acts  to  open  the  valve,  with  the  resulting  increase  in torque, preventing the reduction of engine speed. Fig. 4-132. 4-6-3-4.   REMOVAL AND INSTALLATION (1) Remove air cleaner. (2) Remove ventilation hose. (3) Disengage   air   duct   at   carburetor,   and   remove   it together with air cleaner as an assembly. (4) Disengage accelerator ware from carburetor. (5) Disengage   choke   control   wire   from   engine   and transmission. (6) Disconnect fuel line and remove carburetor. Fig. 4-133.  Removing Carburetor (7) Remove fuel receiver plate, gasket and spacer. (8) Remove pneumatic governor. 4-76