The stop of throttles are no just "stops" but a little (very little) opening for coming air for idle speed. Only for idle speed !!. The little screws of throttles is for adjustment this little opening of throttle.
The big screws on throttles is for additional incoming air when the throttles are little open, (at 1.200-1.900 rpms).
After 1.900 rpms, the opening of throttle are big and the volume of incoming air is big too.. so the big screws not affect the total volume of air (after 2.000 rpms).
So for correct volume of incoming air at 1.200-1.900 rpms the big screws on throttles must be around 2 + 3/4 full turns from closed..
The "take out" of fuse 5, is always for resetting the ECU..
That needed because there is a routine in ECU that measure the start and end of throttles for founding the correct value (on map) for fuel. This routine is "when take out and refit the fuse 5, at the first time open 3 times full the throttles, the ECU "see" the start and end of throttles", that's it. So gives (by the value of map) the correct fuel depending the rpms.
So when you make new setting on TPS the ECU must learn the new start and end of throttles.
I make all these adjustments to many R850-1100-1150, there is no problem - perfect results.. That needed because the engine after many thousand miles the compression (both) at the cylinder is not the same!!
After these adjustments the synchronization is perfect at idle speed, at low revs (1.200-1.900) and at middle and high rpms, this is the only way.. for full synchronization at all revs of rpms..
So step by step :
1. Make a sychronization by cable at 2.500 or 3.500 rpms.
2. Make a sycrhonization by big screws on throttles at 1.400-1.600 rpms.
3. Finally make a repeating sychronization by the little screws behing the throttles for idle speed, but look always the TPS by voltometer and set it always to 0,366 Volts. After new adjust of TPS, take out the fuse 5 and go again to the 3 step, until :
A. the idle speed is 1.050-1.100 rpms (both cylinder)
B. the big screws are 2 + 3/4 (arround) full turn and
C. the TPS is 0,366 Volts (+/-20mV).
If you dont take out the fuse 5, you will not see the correct idle speed, and when you say " i finish" the adjustment of idle speed, at the next starting of engine you will see another idle speed!!
Although you can probably get the above procedure to work, this is a reversing of the usual alignment steps that leads to a lot of back and forth adjustment. The procedure outlined in the BMW service procedure is direct and efficient.
So that someone reading this thread in the future questions whether the above, novel procedure is correct, I want to mention a few things:
1) In a closed loop motorcycle with oxygen sensor there is no need to reset the Motronic during TB sync and alignment. The air for idle is controlled by the BBSs, and the fuel is controlled by lambda.
2) Although it is commonly believed that the Motronic learns the end points, here is what BMW says:
Switch on the ignition.
• Withoutstartingtheengine,fullyopenthethrottle
once or twice so that the Motronic control unit can
register the throttle-valve positions.
I've made many tests to see if the end points are learned, they aren't. To be aligned properly, you only have to adjust the tps until a) an led on the r1100 diag connector signals alignment, b) a gs-911 signals r1150 alignment or c) the tps voltage is as close to 350 mV as you can get it. After that, the Motronic doesn't care.
So if the Motronic isn't learning the end points when you rotate the throttle twice, what is it learning? Probably the crossover point between the two different pots inside the tb package.
3) The TPS is not an adjustment for idle speed, so don't use it for that. The primary adjustment is the BBS (Big Brass Screw) on the TB, which adjusts airflow.
An exception is on a non-catalytic converter R1100. In that case the CO Pot and BBSs do interact somewhat.
It is a good idea to leave the TB stop screws and TPS alone if they have original paint on them. If someone has already played with them, then you might need a process to bring them back. zero=250 will get you as close as you can. In that procedure you follow zero=zero but set the TPS at 250 mV with the left tb fully closed (rather than 0-10 mV as suggested in z=z) and use the throttle stop screw to move it just a little to about 350 mV, then finish the z=z procedure. BtW, that will result in the BBSs being opened the proper amount. Don't forget to clean the BBS passages as needed before the procedure.
