Rotax 125 MAX evo Repair Manual page 65

2. Right thickness of solder
2.0 mm (for 125 MAX only)
3.0 mm (for 125 Junior MAX only)
bend as shown in the Figure: "Squish gap measurement" and insert through the spark plug
thread into the combustion chamber until the solder is in contact with the cylinder wall.
The squeeze edge must always be measured in the direction of the axis of the piston pin. Di-
vergent measurements will show a wrong result!
3. Rotate the starter gear assembly by hand over the TDC position.
N N O O T T E E
This will squeeze the solder between the piston and the combustion chamber
insert.
4. Remove the solder from the combustion chamber and measure the thickness at the very
end (= "squish gap") of the crushed end of the solder with a vernier calliper.
N N O O T T E E
A vernier calliper with an accuracy of min. 1/100 mm is required for this
measurement.
You find the latest valid reglement on:
http://www.rotax-kart.com/de/Max-Challenge/MAX-Challenge/Regulations.
N N O O T T E E
We recommend setting a squish gap in the upper tolerance range of the relevant
model.
N N O O T T E E
The squish gap can be set to a different thickness with cylinder base gaskets. Cyl-
inder base gaskets are available 0.2 mm (0.008 in.), 0.3 mm (0.01 in.), 0.4 mm
(0.015 in.), 0.5 mm (0.02 in.) and 0.8 mm (0.03 in.) thick.
Engine model: A cylinder base gasket 0.5 mm thick has been installed. With this cylinder base gasket a
125 MAX – squish gap of 0.8 mm was measured. A cylinder base gasket 0.8 mm thick is required to
EXAMPLE set the required value, e.g. 1.1 mm.
Of course a 0.5 mm and a 0.3 mm seal can be installed.
If it is necessary to install a cylinder base gasket with a different thickness, the cylinder
can be completely removed by unscrewing the four studs. Follow the instructions in sec-
tion "Installation of the cylinder".
Keep in mind that the gasket will settle and reduce the squish over time.
Chapter 4
Page 32
BRP-Rotax
REPAIR MANUAL
ATTENTION
The squish gap must be within the specified tolerance.
Effectivity: 125 MAX evo, Junior MAX
evo, Mini MAX evo, Micro MAX evo
Edition - February 01 2018 /Rev. 0