Exhaust Outlet Slider Function; Disassembly Of The Exhaust Outlet Slider - Rotax 125 MAX DD2 Repair Manual

Exhaust outlet slider function

◆ Note:
The engine has a pneumatic exhaust outlet control to optimize the
performance characteristics. Air pressure controls the slider bellows via
the impulse bore. The slider piston pulls up the exhaust outlet slider and
thus provides a longer outlet control time. The fuel throughput and therefore
also the power is increased.
◆ Note:
Adjustment to determine the optimum opening of the outlet slider can only
take place under load - on the track, during actual operation. The exhaust
gas temperature has a decisive influence on the opening behavior of the
outlet slider. The temperature curves during driving operation are completely
different to those obtained on the engine test stand and during idling.
Therefore the adjustment and changes to the adjustment of the outlet slider
during idling are not suitable for predicting performance behavior during
actual driving operation.

Disassembly of the exhaust outlet slider

➩ Release the spring clip (Item 1).
➩ Remove and store the slider cover (Item 3), complete with adjuster screw (Item 2)
and pressure spring (Item 4).
➩ Lift away the outer tubular spring (Item 7).
➩ Unscrew the slider piston (Item 5) using a T-spanner.
➩ Remove the inner tubular spring (Item 8) from the slider bellows (Item 6), push out the
slider bellows from the slider piston.
➩ Free the slider guide, lower portion (Item 9) from the cylinder (Item 16) by undoing the
2 screws (Item 11). Remove the gasket (Item 10) and washer (Item 12).
➩ Remove the outlet slider (Item 15) with o-ring (Item 14) and stud bolt (Item 13).
◆ Note:
If the outlet slider or the stud bolt is replaced, on installation these must be
secured with Loctite 221.
Page 17
Repair Manual 125 MAX DD2
Fig. 15
Issue 01/2006