Forum bmwbike.com

I don't know if anyone on this forum has tried this product but I visited the MZ-B offices in Berlin 3 years ago and bought an alternator kit for installation into an R25/2 with a sidecar. All the components are supplied, right down to cable ties. After reading the instructions (twice) it took me all of 1 hour to install the entire kit. As my bike had been locally converted to 12 volts anyway, there was no requirement for changing lightbulbs etc. I have now been running this conversion kit for 3 years and it is totally reliable. The major advantage is not having to reset points and mess around with the timing. The only disadvanntage was that I wanted to continue using a battery and thus the problem of where to put everything ( regulator, coil and advance unit)could only be solved by using a false battery for the bits and installing the battery in my sidecar boot. No problems after that.

The installation of the MZ-B kit into a /2 is more difficult. Many people have reported that the instructions are poor and some of the parts don't fit. A local restorer installed a kit in an R60US and I made these photos describing some of the problems:
http://www.flickr.com/photos/roundel/sets/466723/

I have a restored R27 whose new generator and rotor developed a fault in 2003 after a year of use. MZ-B did not make an R27 kit at that time, and my solution was to install a 12V kit made of /5 parts and sold by an retired BMW dealer. If I have any further problems, I would try the MZ-B kit which is now available.

I have just fitted an MZ 12V kit to my R27. It was easy to instal, had good instructions, with one minor omission (unclear dip switch setting data, quickly confirmed by MZ), and seems to work very well. The only real problem is that as the system is split, with one coil for the spark and the others for the charging function, the battery circuit does not support the spark, so you need a pretty substantial kick to get the thing going, especially with the standard Bing. The guys at MZ say 300rpm but I would say it's a bit more than that. Most of the time I rock it back onto compression and bump start it in 2nd gear. I really like the additional lighting (H4 headlight etc) so I'm working on a mod to use the battery on the coil as well, as the old system was easy to kick start. There are a series of dip switches on the advance unit that allow different curves but thats really a bit over the top and the standard 7 / 42 advance at 4000 works fine. It's not cheap but it's an easy installation.

I have a 12v system adapted from a /5 in my R27. The battery makes the spark, and it starts extremely easily.