TM  5-2815-241-34&P FUEL   PUMP   CALIBRATION   -   CONTINUED ACTION LOCATION ITEM REMARKS GOVERNOR CUTOFF RPM TESTING - CONTINUED 27.   Continued Fuel  pump  (1) g. If cutoff rpm is too low, remove barrel assembly  cover  (2)  and  add  shims.  If cutoff rpm is too high, remove shims. (See  Fuel  Pump,  page  2-289.) Each 0.001 in. (0.025 mm) shim thickness  will  change  speed  approxi- mately  two  rpm.  Shims  are  available  in 0.005-, 0.007-, 0.010-, and 0.020-inch  (0.13,  0.18,  0.25,  and 0.51  mm)  thickness. CAUTION Do not hold throttle lever in idle position any longer than necessary to complete test. Pump may overheat, since fuel flow is used to cool the pump. h .   Air must be purged from fuel pump. With fuel pump at 500 rpm, move throttle lever (3) back and forth until rotameter shows no air, and recheck governor cutoff rpm. THROTTLE  TESTING  AND  ADJUSTING CAUTION Do not hold throttle lever in idle position any longer than necessary to complete test. Pump may overheat, since fuel flow is used to cool the pump. NOTE This  setting  controls  fuel  leakage  inside  fuel  pump,  to  control  deceleration  time,  and keeps  fuel  in  all  lines  during  closed  throttle  position,  preventing  air  locks. A test cycle is one-half minute duration. 28.  Test  stand  (4) Fuel  pump  (1)  and throttle  lever  (3) Test  and  adjust  throttle  leakage  as follows: a. Increase  fuel  pump  speed  to  2100  rpm. b. Place  selector  valve  (5)  to  ROTAMETER position. This is to see if any air is In system. c. Set  fuel  flow  control  valve  (8)  for  315 lb/hr    reading. At  2100  rpm,  fuel  flow  should  be  315 Ib/hr. 2-342