BRP Rotax 125 MAX evo - Engine Running-in and Exhaust Valve Timing; Engine Running-in Procedure; Running-in Fuel Mixture and Jetting; Use of Synthetic Two-Stroke Oil

Ope
rator’s Manual ROTAX 125 MAX evo, Junior MAX evo, Mini MAX evo, Micro MAX evo
Pag
e 52/58
Edi
tion 09/2016
7.3. Ru
nning-in procedure for the engine
¢ Attention: Pay attention to safety advice of the kart manufacturer.
To ensure that components have the longest possible lifespan, the engine must undergo a defined
running-in period at first operation or after a repair of the crankshaft or displacement parts.
¿ Note: Cover the radiator with the mounted windshield to reach the operating temperature
earlier.
Observe the following issues:
P Use a two sizes bigger main jet size based on altitude and temperature (see section
4.1.)
P For the first 10 liters of fuel use a mixing ratio of 1:33 (= 3% or 0.3 liter oil per 10
liters fuel).
P Make sure that the coolant temperature reaches 35 °C (95 °F).
P Run the kart for 15 minutes at continuously changing load and engine speed
fluctuation up to maximum rotational speed. Rotational speed for max. 2 seconds!
P Afterwards reduce the main jet size step-by-step until standard size is reached.
After this running-in procedure, the full power of the engine may be used.
¢ Attention: Use only fully synthetic two-stroke oil. BRP-Rotax recommends using XPS Kart-
TEC oil.
¢ Attention: The engine may never be operated without load. Is it operated without load (i.e. on
the trolley), rpm. over 13.800 1/min are possible, which shortens the lifetime of
components (conrod, big end bearing etc.).
7.4. Setting of the exhaust valve timing (125 MAX evo only)
The opening time of the exhaust valve is set in the ECU and depends on the engine speed.
However, the ECU allows two different modes of the exhaust valve opening. These can be
selected by connecting an additional cable to the cylinder head cover.
¢ Attention: The ground wire (pos. 1) must be continuously connected. This is important for the
general function of the engine.
Variant 1: Additional cable on battery ground
A:
See Fig. 8.
The additional cable is NOT attached to the ground wire. The control of the exhaust valve timing is
activated at 7900 rpm.
¿ Note: Isolate the additional cable with an electrical/insulating tape to the ground wire so
that a possible contact with the engine ground does not affect the function.