my specialty:12volt conversion kits for BMW /2 motorcycles




Installing the ignition coil:

ignition coilengine caseignition coil

Left above is the ignition coil. Remove the two bolts from the lower arms. We will mount the ignition coil by slipping the lower arms over the studs shown in the center photo. These are the studs from which we removed the old magneto body. But first, it easier to install the High Tension (HT) cables now before mounting the ignition coil. The HT cable in our kit came as one piece so we will cut it in two, then screw the two cables into the coil as shown in the photo on the right. We will trim the cables to proper length later at the spark plug caps.

ignition coil ignition coil green wirecoil connection

Slip the ignition coil assembly into the two studs and bolt it down using the bolts you saved after removing the old magneto body.. Next, locate the green wire connection at the ignition coil shown in the two center photos and connect it to the the yellow wire connection at the sensor unit on the generator, shown in the right photo.

coil mount

To the left is a photo from the factory instructions to which I have added some numbers to show the suggested routing of the new wires.

(1) the connection of the yellow wire from the sensor and the green wire from the coil

top of engine case(2) the routing of the generator (alternator) wiring harness up and out through the opening at the top of the case.

(3) the routing of the coil wiring harness up and out through the opening at the top of the case

(4) the routing of the HT wires back and out through the opening at the top of the case.

We will later make connections to the generator and ignition coil connectors in the area under the top engine (breather) cover.


Installing the electronic advance unit:

electronic advance unit

clamp paddingThe electronic advance unit is premounted on a plate designed to be fastened to the frame tubes by means of three clamps. We found the the top clamps required a little trimming of the rubber padding while the lower clamp need additional padding. We added switchesa trimmed piece of inner tube to fit the lower clamp (see the photo on the right). I generally add a couple of inner tube strips to kits I ship.

Note that the factory instructions paragraph dealing with mounting the electronic advance unit includes the statement: "Than [sic] screw the new high tension . . .." This appears to be a misprint and has nothing to do with the mounting of the advance unit--ignore it.

On the bottom rear of the electronic advance unit you will see a set of switches. Their function is described in the factory installation booklet in some detail. You can use them to select between two different advance curves. We left these switches set at the factory default.


Installing the voltage regulator:

voltage regulator

To mount the new voltage regulator we unbolted the fuel tank carrier, added the custom plate with the voltage regulator attached, and re-bolted the two pieces back to the frame. When the fuel tank is reinstalled, the new voltage regulator is away from the heat of the engine, positioned to receive good air flow, and is out of view. As you can see in the photo below, you have to be at cylinder level to see the new voltage regulater.

Installed voltage regulator

We followed the factory instructions, but It is also possible to mount both the electronic advance unit and the voltage regulator together under the tank. The photo below is the clever installation that Anton Largiader has on his bike--both the electronic advance unit and the voltage regulator are mounted together up under the tank..

Anton's installation

This photo also is a good shot of the wiring connection we will make next.