stryker 125 Workshop-manual : Page 29

          2. GENERAL INFORMATION                                                                    STRYKER 125/150

 POOR PERFORMANCE (ENGINE LACKS POWER)

 Inspection/Adjustment                              Symptom                         Probable Cause
 Start engine and accelerate
 lightly for observation
                                                                                 Clogged air cleaner
                                                                                 Poor fuel flow (Restricted)
                                  Engine speed           Engine speed does not   Clogged fuel tank cap breather hole
                                  increases              increase sufficiently   Clogged exhaust muffler
                                                                                 Carburetor fuel level too low
 Check ignition timing                                                           Clogged carburetor high speed fuel
 (using a timing light)                                                          passage

                                       Correct                 Incorrect         Faulty CDI unit
                                                                                 Faulty A.C. generator

 Check valve clearance
                                                                                 Improper valve clearance
                                       Correct                 Incorrect         adjustment
                                                                                 Excessively worn valve seat
                                                                                 (protruded valve stem)
 Test cylinder compression
                                                                                 Improper valve and seat contact
                                   Normal                  Low compression       Worn cylinder and piston rings
                                   compression                                   Leaking cylinder head gasket
                                                                                 Improper valve timing
 Check carburetor for
 clogging
                                    Not clogged                Clogged           Clean and unclog

 Remove spark plug and
 inspect
                                 Plug not fouled or        Plug fouled or        Fouled spark plug
                                 discolored                discolored            Incorrect heat range plug
 Check crankcase for oil
 level and condition
                                                            Incorrect or         Oil level too high
                                  Correct and not                                Oil level too low
                                  contaminated              contaminated
                                                                                 Oil not changed
 Check cylinder head for
 oil lubrication

                                Valve train lubricated    Valve train not        Clogged oil line
                                properly                  lubricated properly    Faulty oil pump

 Check for engine overheating
                                                                                 Worn cylinder and piston rings
                                                                                 Mixture too lean
                                  Engine does not                                Poor quality fuel
                                  overheats                Engine overheats
                                                                                 Excessive carbon buildup in
                                                                                 combustion chamber
                                                                                 Ignition timing too advanced
 Rapidly accelerate or run
 at high speed
                                                                                 Excessive carbon build-up in
                                                                                 combustion chamber
                                Engine does not knock       Engine knocks        Poor quality fuel
                                                                                 Clutch slipping
                                                                                 Mixture too lean
                                                                                 Ignition timing too advanced

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