Rotax MMH-912 Series Maintenance Manual page 138

Effectivity 912/914 Series
Edition 1 / Rev. 1
BRP-Rotax
Maintenance Manual
Check the valve face for wear caused by pounding VT03.
Pounding may occur on the inside and the outside edge of the seat
surface and must be measured as shown in Fig. 72-70.
See 72-00-00 sec. 4.
■ CAUTION: The valve seat at the valve disk is surface hardened.
For this reason, the valve disk must not be reworked.
If necessary, the valve must be replaced.
However, lapping with valve lapping paste is possible.
Seal-lap both valves and check for leakage.
■ CAUTION: The end of the valve stem (5) must not be ground.
See Fig. 72-68.
Fig. 72-70
07483
72-00-00
page 66
January 01/2008