Servicing Individual Components; Engine Housing - KTM 125 Repair Manual

SERVICING INDIVIDUAL COMPONENTS

RIGHT HOUSING HALF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2
LEFT HOUSING HALF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3
CRANKSHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4
CRANKSHAFT WEBS – MEASURE OUTER DIMENSION . . . . . . . . . . . . . . . .5-4
PISTON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4
PISTON RING END GAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4
CHECKING CYLINDER FOR WEAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-5
NIKASIL COATING OF CYLINDER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-5
DISMOUNTING AND CHECKING THE EXHAUST CONTROL
SYSTEM IN THE CYLINDER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-6
PREASSEMBLING THE CYLINDER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-7
CLUTCH COVER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-10
PREASSEMBLING THE CLUTCH COVER . . . . . . . . . . . . . . . . . . . . . . . . . . .5-10
WATER PUMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-11
PREASSEMBLING THE WATER PUMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-11
CHECKING CLUTCH FOR WEAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-12
REED VALVE HOUSING, INTAKE FLANGE . . . . . . . . . . . . . . . . . . . . . . . . . .5-13
KICKSTARTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-14
PREASSEMBLING THE KICKSTARTER SHAFT . . . . . . . . . . . . . . . . . . . . . . .5-14
SHIFT MECHANISM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-16
PREASSEMBLING THE SHIFT SHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-16
TRANSMISSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-17
ASSEMBLING THE MAIN SHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-17
ASSEMBLING THE COUNTERSHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-18
IGNITION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-19
CHECK STATOR AND PULSE GENERATOR . . . . . . . . . . . . . . . . . . . . . . . . .5-19

Engine housing

NOTE: Read through the following section before commencing work. Then determine the assembly sequence so that
the engine housing halves only need to be heated up once before replacing the bearings.
Having first removed the dowels, in order to expel the bearings or remove them with light mallet blows, the housing
halves must be placed on a suitably large plane surface, supporting the whole of the sealing surface without damaging
it. A wooden panel is best used as a base.
Bearings or shaft seal rings should not be hammered into their seats. If no suitable press is available, use a suitable
mandrel and hammer them in with great care. Cold bearings will practically drop into their seats at an engine housing
temperature of approx. 150° C.
After cooling, should the bearings fail to lock in the bore, they are bound to rotate after warming. In that event the
housing must be replaced.
INDEX
5-1C
5