- Engine flywheel sensor, allows you to know at what engine speed the engine is running
- Intake air temperature sensor (in the air box)
- Water temperature sensor
- Intake vacuum sensor (in the air box)
- Throttle Position Sensor (TPS)
All this makes it possible to control the injectors, by regulating the injection time, the quantity of fuel injected is precisely controlled.
Then an additional device (the secondary throttle) is added to moderate the opening speed of the accelerator and control the idle speed.
So we add :
- Secondary shutter actuator (motor)
- Secondary shutter position sensor
- Accelerated idle system
A top view of the injection (tank up, air box removed):
The sensors/actuators of the air box :
SECONDARY THROTTLE SYNCHRONISATION
This adjustment is purely mechanical and should not move over time. It is not of primary importance either, as the throttle is usually open enough so that the influence of the sync is negligible.
First of all, we start by disconnecting the STVA coupler (the engine that operates the secondary throttle valve) by unplugging its connector, as shown in the photo below:
The shutter is then operated by turning this knob by hand:
Then for adjustment, the technical journal recommends measuring the length between the throttle valve and the top of the injection body. Personally I don't find this very precise and I preferred to proceed as follows:
I slide a 0.30 wedge between the butterfly and the body and then I close the butterfly with the wheel until I get a "greasy" rub (rubs but passes anyway). Then I remove the wedge and take the same measurement on the other body. (We start with the front cylinder). If the wedge floats or doesn't pass, you have to adjust the synchro, like this:
STPS SENSOR ADJUSTMENT
Once set, we tighten the sensor and check that it hasn't moved.
TP SENSOR ADJUSTMENT
Sensor view :
I've managed to set it so that it's about in the middle of the range between the bottom line and the top line. After retightening, check that the setting has not moved. You can then reconnect the STVA contactor.
FAST IDLE ADJUSTMENT
Once everything else is set, only the fast idle is left to finish setting. This will be done in two phases, first the standard idle setting and then the fast idle.
For starters, the standard slow motion. We let the bike warm up on the stand until it reaches 80 degrees. The idle speed is then adjusted to 1300 rpm using the screw on the left side, near the frame. Once this is done, let the bike cool down completely.
View of the idling system :
In fact, the secondary throttle allows the primary throttle to be half-opened (and thus accelerate the idle) when it is wide open. The ECU uses it to manage the accelerated idle speed during the warm-up phase of the engine.
THROTTLE VALVE SYNCHRONISATION
Once all this is done, we move on to synchronisation. Before doing so, the air box is completely re-installed and the engine is allowed to warm up to 80 degrees. Once it is hot, we switch off the ignition and connect the regulator to the vacuum sockets.
The device, a twinMax :
Before changing the setting, it is switched on and the sensitivity is set to max. The indicator is then set to zero.
View of the vacuum connection of the front cylinder :
View of the rear cylinder vacuum connection :
The aim is for the twinMax indicator to be as close to the middle as possible. When adjusting, the idle speed may increase, we will then reset it to 1300 rpm and confirm that the sync is still ok.
Once it's done, remove the twinMax, put the caps back on and it's ready for a little ride!