Piston Rings - Inspection - Rotax 915 i A series Maintenance Manual

NOTE
If the determined installation clearance is great-
er than the permissible installation clearance,
the piston and/or cylinder must be replaced.
Step Procedure
5 Determine the diameter of the piston pin
bore. See Chapter 72-30-10 section
Wear limits.
NOTE
The flank clearance can be measured on the in-
stalled rings using a feeler gauge. Multiple de-
posits in the spiral expander of the oil scraper
ring suggests that AVGAS 100LL has been
used.
Figure 9.9
1 Piston
Feeler gauge
3
PISTON RINGS — INSPECTION
Procedure
Step
1 Check the cleaned piston rings for piston
ring joint clearance.
Effectivity: 915 i A Series
Edition 0/Rev. 0
BRP-Rotax
MAINTENANCE MANUAL HEAVY
Ring grooves
2
NOTE
To determine the piston ring joint clearance, re-
move the piston rings with piston ring pliers,
clean them and place them in the cylinder.
Aligned with a piston in the cylinder and pushed
approx. 10 mm (0.3937 in.) from the upper edge
into the cylinder.
Step Procedure
2 Measure the piston ring joint clearance
using a feeler gauge. See
10 section Wear limits
NOTE
Examine the ring surface closely to identify the
supporting part and thus also the wear which
has already taken place.
Figure 9.10
Cylinders
1
Feeler gauge
3
Chapter 72-30-
(PI07).
2 Piston ring
72–30–10
Page 9
August 01 2018