TM 5-4240-501-14P GENERAL INFORMATION Check-up Check Carburetion Before  making  a  Carburetion  check,  be  sure  the   fuel tank has an ample supply of fresh, clean gasoline. On  gravity  feed  (Flo-Jet)  models,  see  that  the shut-off  valve  is  open  and  fuel  flows  freely  through  the fuel  line.  On  all  models,  inspect  and  adjust  the  needle valves. Check to see that the choke closes completely. If engine will not start, remove and inspect the spark plug. If plug is wet, look for - 1. Overchoking 2. Excessively rich fuel mixture 3. Water in fuel 4. Inlet valve stuck open (Flo-Jet carburetor) If plug is dry, look for - 1. Leaking carburetor mounting gaskets 2. Gummy or dirty screen or check valve (Pulsa-Jet and Vacu-Jet carburetors) 3. Inlet valve stuck shut (Flo-Jet carburetors) 4. Inoperative pump (PulsaJet carburetors) A  simple  check  to  determine  if  the  fuel  is  getting  to  the combustion chamber through the carburetor is to remove the   spark   plug   and   pour   a   small   quantity   of   gasoline through  the  spark  plug  hole.  Replace  the  plug.  If  the engine  fires  a  few  times   and   then   quits,   look   for   the same condition as for a dry plug. Equipment - Effecting Engine Operation Frequently,  what  appears  to  be  a  problem  with  engine operations, such as hard starting, vibration, etc., may be the   fault   of   the   equipment   powered   rather   than   the engine itself. Since many varied types of  equipment  are powered    by    Briggs    and    Stratton    engines,    it    is    not possible to list all of the various conditions that may exist. Listed    are    the    most    common    effects    of    equipment problems,  and  what  to  look  for  as  the  most  common cause. Hard Starting, Kickback, or Will Not Start 1. Loose blade must be tight to shaft or adapter. 2. Loose  belt  a  loose  belt  like  a  loose  blade  can cause  a  back-lash  effect,  which  will  counteract engine cranking effort. 3. Starting under load See if the unit is disengaged when engine is started; or if engaged, does not have a heavy starting load. 4. Check  remote  Choke-A-Matic  control  assembly for proper adjustment. 5. Check  interlock  system  for  shorted  wires,  loose or  corroded  connections,  or  defective  modules or switches. Vibration 1. Cutter blade bent or out of balance Remove and balance 2. Crankshaft bent - Replace 3. Worn blade coupling - Replace if coupling allows blade to shift, causing unbalance. 4. Mounting bolts loose - Tighten 5. Mounting    deck    or    plate    cracked    Repair    or replace. Power Loss 1. Bind or drag in unit If possible, disengage engine and    operate    unit    manually    to    feel    for    any binding action. 2. Grass cuttings build-up under deck. 3. No lubrication in transmission or gear box. 4 Excessive drive belt tension may cause seizure. Noise 1. Cutter  blade  coupling  or  pulley  an  oversize  or worn  coupling  can  result  in  knocking,  usually under acceleration.  Check for fit, or tightness. 2. No lubricant in transmission or gear box. 1 7