Derbi Dirtboy 10 Workshop Manual page 40

E E ENGINE
E N G I N E
- Rest the flywheel-side crankcase-half on a flat surface,
adequately supported and with the crankshaft vertical.
- Insert the timing chain positioning it at the edge of its
housing so that in won't interfere with the refitting of the
crankshaft assembly, the bearing, and the timing gear-
shaft.
- Heat the crankcase-half up to approx. 120 °C, using a heat
gun.
- Install the bearing on the crankcase with utmost care in
order to avoid damaging the bearing housing.
I I
NSPECTING THE CRANKSHAFT ALIGNMENT NSPECTING THE CRANKSHAFT ALIGNMENT
Place the crankshaft on the stand and measure the runout at
the three points shown in the figure.
Check the condition of the crankshaft cone, the tab seat, the
oil seal bearing, the knurled pin and the threaded tangs. If
any anomalies are found, replace the crankshaft.
NB
IF THE RUNOUT MEASUREMENTS SLIGHTLY EXCEED THE
SPECIFIED LIMITS, TRY TO STRAIGHTEN THE CRANKSHAFT
BY INSERTING A WOODEN WEDGE BETWEEN THE SHAFTS
OR, IF NECESSARY, BY CLAMPING THEM IN A VICE. IF,
DESPITE THE STRAIGHTENING, THE VALUES ARE NOT AS
SPECIFIED, PROCEED TO REPLACE THE CRANKSHAFT.
Specific tooling
020074Y Crankshaft aligning tool
020335Y Magnetic stand and comparator
C
HARACTERISTIC
Max allowable misalignments:
A = Ø 0,05 mm
B = Ø 0,04 mm
C = Ø 0,04 mm
40
- CRANKCASE - CRANKSHAFT
- CR ANKCAS E - CRA N KSH AFT