TM  10-3930-653-14&P Compression pressure: 11.0 kg/cm2 (156 psi) at 300 rpm Difference between individual cylinders: Less than 1.0 kg/cm2 (14 psi) at 300 rpm (6) MEASURING   SUCTION   (VACUUM PRESSURE) (1) Replace        elbow        connector        (for        vacuum pressure) on intake manifold suction (vacuum) plug hole with a nipple (for measurement). (2) Install a vacuum gauge on nipple. (3) Operate   engine   at   Idling   speed   and   measure suction (vacuum pressure). Standard value: -43 mmHg (-16.93 inHg) or higher Fig.  4-5. Measuring Suction ( Vacuum pressure). (7) LUBRICATING  ACCELERATOR LINKAGE Apply a light coat of multipurpose grease to all sliding or friction surfaces except ball joints.  The entire linkage should   be   inspected   whether   or   not   the   acceleration pedal  returns  to  normal  height  smoothly  when  releasing It.  This test should be made with engine running Added care should be taken in checking items that affect proper linkage function. (8) CHECKING GOVERNOR OPERATION Check maximum engine speed under no load as follows: (1) Shift transmission gears into neutral. (2) Run  engine  and  set  carburetor  throttle  valve  at fully-open position.  Check engine rpm. Maximum engine speed Under no load: 2950 to 3080 rpm H20PU240 (3) If   engine   speed   is   not   within   specified   range, adjust it by turning governor adjusting screw handle. 1  Adjusting screw handle 2 Adjusting spring handle Fig.  4-6. Check maximum engine speed under load as follows: (1) Shift    transmission    gears    into    neutral.        Run engine   with   mast   assembly   tilted   fully   backward   with hydraulic control lever. (2) With     carburetor     throttle     valve     at     fully-open position, check engine rpm. Maximum engine speed under load: 2,800 to 3,000 rpm (3) If   engine   speed   is   not   within   specified   range, adjust It by turning governor adjusting spring handle.   Also adjust maximum engine speed under no  load. 4 - 10