TM 5-3895-383-24 Fuel Ratio Control Setting This is an on engine test to determine if the FRC (Fuel Ratio Control)   is   set   properly.      If   the   FRC   is   set   properly,   no additional   procedures   will   be   needed.      If   the   FRC   is   set incorrectly,   the   governor   must   be   removed   and   adjusted according to Governor Bench Testing and Adjusting Procedures, in 3114, 3116 & 3126 Governor Service Manual, SENR6454. To determine the FRC settings, complete the following steps: 1. Install Fuel Setting Indicator Group as instructed in the "Fuel Setting" section of this manual. NOTE: A    digital    indicator    is    recommended    for    the following test procedures. NOTE: If  desired,  a  modified  valve  cover  presented  in June 1993 "Engine News" can be installed.  This will   prevent   oil   loss   during   completion   of   this procedure. Typical governor. (1) FRC (Fuel Ratio Control).  (2) Boost line port.  (3) Low idle screw.  (4) High idle screw. 2. Disconnect  the  boost  line  from  the  boost  line  port  (2) and apply air pressure to the boost line port (2). NOTE: A regulated air supply of 140 to 270 kPa (20 to 30 psi)  MUST  be  used  to  avoid  damage  to  the  fuel ratio control. 3. With the engine operating a low idle quickly actuate the throttle to high idle position. 4. Record  the  maximum  reading  observed  on  the  digital indicator  as  the  engine's  speed  increases  to  high  idle. This   is   the   dynamic   maximum   fuel   setting   value. Repeat  the  procedure  several  times  and  average  the values. NOTE: Static  and  dynamic  engine  rack  values  may  vary due  to  the  method  of  fuel  setting  calibration  and differences in governor settings.  When adjusting the "on engine" fuel setting statically,     a calibration pin is used as the reference dimension to the governor.  This pin is used on all engines regardless  of  governor  settings.    This  common calibration  point  along  with  different  settings  in the  governor  will  cause  the  engine  dynamic  and static   rack   values   to   differ   depending   on   the governor    part    number,    since    the    load    stop settings  range  between  9.0  mm  (.35  in)  and  10.4 mm (.41 in).  When the pin is in place the governor travel  is  restricted,  but  when  the  pin  is  removed and    the    engine    is    running,    the    governor    is unrestricted.    This  allows  a  higher  dynamic  rack value   than   can   be   obtained   statically   with   the calibration pin in place. 5. Disconnect the air pressure from the FRC and vent the FRC to atmosphere. 6. With  engine  operating  at  low  idle,  quickly  actuate  the throttle to high idle position. 7. Record maximum reading observed on digital indicator as the engine's speed increases to high idle.  This is the FRC setting value.  Repeat the procedure several times and average the values. 8. Subtract   the   FRC   setting   value   obtained   from   step seven  from  the  dynamic  maximum  fuel  setting  value obtained   from   step   four.      This   difference   is   the   on engine FRC delta. 9. Determine  the  governor's  FRC  delta  by  the  following calculation.      Subtract   the   FUEL   RATIO   CONTROL specification from the LOAD STOP specification.  This difference is the governor's FRC delta. NOTE: Refer to the TMI (Technical Marketing Information) Governor Bench Performance Data for the correct FUEL RATIO CONTROL and LOAD STOP specifications. 10. If   the   on   engine   FRC   delta   is   within   ±   .20   mm (  .008  in)  of  the  governor  FRC  delta  specifications, then the FRC is set properly. 11. If  the  on  engine  FRC  delta  is  out  of  tolerance,  the governor will need to be removed from the engine and set to specification on the 1U7326 Governor Calibration Bench. NOTE: For  further  information  on  the  1U7326  Governor Calibration   Bench,   refer   to   3114,   3116   &   3126 Governor Service Manual, SENR6454. 6-70