With the 125 ccm long life-engines the exhaust control comes now enhanced onto the Kart market. Its function is to hold the torque over a bigger speed range as high as possible.
Therefore a valve varies the control edge at the outlet slot. With revs under 7500* the valve gets pushed down by a spring in the outlet port and gets opened over the exhaust pressure by a diaphragm. The preload of the spring is over the blue hand wheel adjustable. The deflection of the valve is roughly 6 mm.
Power drain Rotax engine
To see if the valve is functioning correctly (opens quite fast) and if the preload of the spring is correct set (opens with a Rotax max. at 7500 rpm) there is now a displacement sensor, which gathers the position of the valve without touching it, because the interaction of spring force – reset force of the membranes – exhaust gas pressure –the friction of the valve in its guide mustn’t be disturbed.
The sensor is delivered in a Kit with a hand wheel and can be used in connection with a MyChron 3 extreme, MyChron 4 extreme or MyChron Expansion. With these devices the valve position is also shown in the display.
Connector types Power valve sensor
Pinout Power valve sensor
 |
Pin 1
|
Signal
|
|
Pin 2
|
GND
|
|
Pin 3
|
n.c.
|
| Binder 719, male, solder view |
Pin 4 |
Refence Voltage
|
Compatibility Power valve sensor
 |
 |
 |
 |
|
|
|
| Channel Expansion |
e-Box
eXtreme |
evo4 |
MyChron
Expansion |
|
|
|