Inspection Of The Piston And Cylinder Sizing - Rotax 125 MAX evo Repair Manual

INSPECTION OF THE PISTON AND CYLINDER SIZING

General
N N O O T T E E
Every new piston has the size classification and a production letter printed on the
top of the piston (piston crown).
N N O O T T E E
Every new cylinder has the size classification stamped on the upper sealing
surface.
Measuring the cylinder diameter:
1. Measure the cylinder diameter 10 mm below the upper edge of the cylinder. This dimension
indicates the selection of the matching piston. If the dimension has reached the wear limit of
54.045 mm, the cylinder must be replaced.
2. Measure the piston diameter as described in chapter 4 "Inspection of the piston diameter"
and install a piston to match the required clearance at 0.060 mm +/- 0.005 mm between pis-
ton and cylinder.
Cylinder classification
Piston classification "f"
Chapter 4
Page 14
REPAIR MANUAL
Cylinder labeling
"A"
"AB"
"B"
Piston labeling Tolerance field
"f" 53.95 +0.005 / -0.025 mm
"f" 53.96 +0.005 / -0.025 mm
"f" 53.97 +0.005 / -0.025 mm
"f" 53.98 +0.005 / -0.025 mm
"f" 53.99 +0.005 / -0.025 mm
BRP-Rotax
Minimum dimen-
(mm)
Cylinder dimension
54.000 - 54.010 mm
54.010 - 54.015 mm
54.015 - 54.025 mm
Maximum dimen-
sion (mm) sion (mm)
53.925
53.935
53.945
53.955
53.965
Effectivity: 125 MAX evo, Junior MAX
evo, Mini MAX evo, Micro MAX evo
Edition - February 01 2018 /Rev. 0
53.955
53.965
53.975
53.985
53.995