Yamaha SR125 1997 Service Manual page 235

EB90000
NOTE:
The following troubleshooting does not cover all the possible causes of trouble. It should be helpful,
however, as a guide to troubleshooting. Refer to the relative procedure in this manual for inspection,
adjustment and replacement of parts.
SR90000
STARTING FAILURE/HARD STARTING
FUEL SYSTEM
Fuel tank
: Empty
: Clogged fuel tank cap breather hole
: Deteriorated fuel or fuel containing water or
foreign material
Fuel cock
: Clogged fuel hose
: Clogged fuel cock
COMPRESSION SYSTEM
Cylinder and cylinder head
: Loose spark plug
: Loose cylinder head
: Broken cylinder head gasket
: Broken cylinder gasket
: Worn, damaged or seized cylinder
Piston and piston ring
: Worn piston
: Worn, fatigued or broken piston ring
: Seized piston ring
: Seized or damaged piston
STARTING FAILURE/HARD STARTING
TROUBLESHOOTING
Carburetor
: Deteriorated fuel or fuel containing water or
foreign material
: Clogged pilot jet
: Clogged air passage
: Improperly set pilot screw
: Clogged pilot air passage
: Improperly sealed valve seat
: Improperly adjusted fuel level
: Clogged starter jet
: Damaged carburetor joint
: Improperly tightened carburetor joint clamp
hose
: Starter plunger malfunction
: Clogged emulsion (heated water) tube
: Sucked-in air
Air filter
: Clogged air filter element
: Improper air filter setting
Valve system
: Improperly adjusted valve clearance
: Improperly sealed valve
: Improperly contacted valve and valve seat
: Improper valve timing
: Broken valve spring
: Seized valve
8-1
TRBL
SHTG