Inspection And Adjustment Of Squish Gap - Rotax 125 MAX evo Repair Manual

Figure 4.29: Combustion chamber insert
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INSPECTION AND ADJUSTMENT OF SQUISH GAP

General
N N O O T T E E
The gap between the piston (at the TDC of the piston) and the combustion cham-
ber insert (= "squish gap") is partly responsible for the power characteristics of the
engine and responsible for smooth running.
N N O O T T E E
The smaller the squish gap the higher the engine compression. This means that
the engine response to the feed from the carburetor becomes more critical under
changing operating conditions (temperature, air pressure, humidity).
Special tools The following special tools and equipment are required:
Instructions See
1. Rotate crankshaft by hand until the piston is approx. 5 mm below TDC.
Effectivity: 125 MAX evo, Junior MAX
evo, Mini MAX evo, Micro MAX evo
Edition - February 01 2018 /Rev. 0
BRP-Rotax
REPAIR MANUAL
O-ring 23.3x2.4
1
Cylinder head cover red
3
Part no.
580130
580132
n.a.
Figure: Squish gap measurement.
O-ring 64x2
2
4 Allen screw M6x25
Description
Solder 2 mm
Solder 3 mm
Vernier caliper
Use
Combustion chamber
Combustion chamber
Solder
Chapter 4
Page 31