Piston And Piston Ring - Rotax 125 MAX DD2 Repair Manual

Piston and piston ring

✔ Inspect the piston for pressure points, cracks
and signs of scuffing.
✔ Inspect the bore of the piston pin for damage
and wear.
✔ Inspect the piston pin circlips for defects.
✔ Check for ease of movement of the piston ring
in the ring groove.
◆ Note:
If oil carbon prevents the free
movement of the piston ring, the ring
groove can be cleaned out with a
discarded piston ring.
✔ Carry out the measurement of the piston ring
play in the ring groove, indicated in Fig. 49, using
a feeler gauge.
◆ Note:
If the piston ring clearance has
reached the wear limit of 0.1 mm, the
piston must be replaced.
➩ Remove the piston ring and insert a feeler gauge
into the cylinder parallel to the head sealing
surface, as shown in Fig. 50.
✔ Using the feeler gauge, measure the end
clearance.
◆ Note:
If the wear limit of 0.8 mm has been
reached the piston ring must be
replaced.
Page 33
Repair Manual 125 MAX DD2
Fig. 48
Fig. 49
Fig. 50
Issue 01/2006