Gear Box - Rotax 125 MAX DD2 Repair Manual

➩ Take one housing half from the oven with the
bearings facing upwards.
➩ Turn the housing half over and swing it lightly
onto a flat surface, preferably of wood.
➩ In most cases it will be sufficient to unseat the
ball bearings. If further attention is required to
unseat the bearings, use a plastic hammer for
the purpose.
◆ Note:
The ignition side housing half (Item
1) has two dowel pins (Item 2), see
Fig. 40. Drill corresponding cutouts
in the wood or plastic plate to
accommodate these.
➩ Carry out the same procedure with the clutch-
side housing half, see Fig. 41.
➩ Thoroughly clean the bearing seats.
✔ Measure the bearing seat.
✔ Measure the outer diameter of the bearing.
◆ Note:
When measuring the fit of the
bearings the housing halves must
have cooled to room temperature
(20°C).
■ Attention: The interference fit between the ball
bearing and the bearing seat must be
at least s = 0.01 mm.
■ Attention: If the interference fit is less than this
the housing halves must be replaced.
➩ Heat up the housing halves again to 150°C for
10 minutes.
➩ Lay a housing half on a flat surface.
➩ Insert the ball bearing in the bearing seat in the
housing half.
✔ The closed side of a bearing faces the
component, see Fig. 42.
■ Attention: Crankshaft main bearing: The closed
cage side faces the crank web, see
Figs 40 and 41.
◆ Note:
Do not tilt the ball bearing when inserting it, allow the housing half to cool with the bearing
inserted.

Gear box

Page 29
Repair Manual 125 MAX DD2
Fig. 40
Fig. 42
Issue 01/2006