I've been laying on the miles on the K100RT. Enjoying every meter.

Lately my voltage (as measured by a VDO dash guage) is low, hovering around 12-12.5 with my high beam on. So I figured rather than try to replace the diode and brushes on the old alternator, I'd upgrade to the high output one.

The upgrade is to get the 60amp unit from the K1100, right? Can I use an alt from a 2002 K1200?

Thanks!
SS

Hi Scottie,
Do you have a heavy load? the problem may be nothing more than worn regulator brushes. The regulator is fitted onto the end of the alternator and can be removed without taking the alternator out. If he brushes are worn down that will definitely give you problems with output. Replacing the brushes or even replacing the regulator is way cheaper than even a s/h high power alternator and they will suffer from the same problem in about the same amount of time as your current one.
Regards,
K-BIKE

Thanks for the feedback. Yes, I know I can replace the brushes, however I've been wanting to upgrade to the high output alternator and now seems to be the right time.

Found this...
http://www.bmwmoa.org/forum/showthread.php?t=29720

The ideal upgrade is the 60 amp alternator from an Oilhead (Type R259) that you'd want to source for your early K model. Note that you will need to adapt the rotor or connector to make it fit. Here's the list of bits: This retrofit will require adaptor kit
with new alternator clutch housing (BMW # 12 31 2 305 329), driving dog
(BMW # 12 31 1 460 304) and rubber mounting dampers (BMW # 12 31 1 464
877 x 3).

Here's a link with some useful info from John at Euro Moto Electrics.

http://www.euromotoelectrics.com/product_p/bmw-alt3-fslash-955.htm