Reportedly, Valeo starters tend to fail over time due.
The most frequent failure seems to be due to "lost magnets". These magnets are part of the starter motor itself and are glued to the outer part of the housing; over time, they may simply fall off (probably due to thermal and/or mechanical stress). Loss of one or two magnets may go unnoticed at first, but the resulting debris may block the starter motor in the most unconvenient moments 
It is well possible to repair such a defective starter (there are several descriptions about this on the web; see the link list at the end of this section), but it is probably more efficient to re-use a complete starter motor from a car junkyard. Valeo starters of the type we need were used in a number of smaller cars, such as Opel Corsa, Astra, Kadett; Renault Clio; Citroën AX, BX and C15; Peugeot 205, 206, 306, 307, 309, 405, etc. Those who live in the USA may want to look for Saturn cars. Do not worry too much about the shape of the cast aluminium cone; the important point is that you ask for a Valeo DR6RA or DR6A. (It seems that the starter of the Renault Laguna is even a true 1:1 replacement for the complete BMW part?) - The part swap is pretty straightforward. On both starters, proceed as follows:
Remove the starter from the bike, as described in the previous section.
Remove the starter "gearbox" as described (three Allen-head bolts, one Torx T20). At this point, you will notice a big similarity between the two assemblies; the major "visual" difference is indeed the aluminium-cast housing of the planetary gearbox "nose". It is tempting to do a "quick swap", but be careful: count the number of teeth on the cogwheel; you will need exactly 9!
The starter motor housing is attached to its base plate with two rivets. Drill them out.
Unscrew the short, thick wire that is connected to the starter solenoid (13-mm key).
Carefully withdraw the motor from its base plate.
Clean out the dirt that is eventually present, then swap the starter motors.
Reassemble in reverse order
. You do not need to replace the rivets, since the three Allen-head bolts will hold the complete unit together.
