When I had the heads rebuilt by Randy Long I had him modify them for dual plugs. I have made that modification on two other bikes and I like the improvement in gas mileage and the smooth running even on lower octane gas. So I have to replace the stock coils with coils that have two secondary ports so each coil connects to two spark plug wires.
This bike came with a BMW electronic ignition that includes a “bean can” with Hall effect sensors that act like mechanical points.
BMW Stock Ignition Sensor (aka “Bean Can”) with Hall Effect Sensors
The Hall effect sensors use a rotating magnetic field to open an electronic switch in the Hall effect sensor to stop current flow in the coil primary triggering a large voltage in the coil secondary. This is exactly what mechanical points do to trigger a high voltage spark in the spark plugs.
There have been some issues with the BMW electronic ignition. One in particular is that Hall effect sensors do not like heat and fail over time. When they do, you are stranded unless you have a second bean can with you. You can’t remove and disassemble the bean can by the side of the road.
I decided to remove the stock BMW ignition system and install a system that uses an optical switch for the points and a electronic ignition control module from Euro MotoElectrics. The ignition control module has three different ignition advance curves you can select from including one that works well with dual plug engines.
EME Optical-Electronic Ignition Kit
Since I have dual plug heads, I also install dual port coils.
EME Enduralast 1.5 Ohm Dual-Port Coils with Hardware
You can read about how I do this work here:
And, this is a video summary of the procedure.
VIDEO: 1983 BMW R100RS Install Euro MotoElectrics Optical-Electronic Ignition System
Here is what the final installation looks like.
Optical Trigger Assembly with Timing Wheel Mounted On Alternator Rotor
Ignition Control Module Mounted On Top Of EME Electronic Voltage Regulator
Dual Plug Coils Mount Where Original Coils Mounted
such a great video, thanks! Wondering if I can use that system somehow on my ’78 R80/7 – no bean can, so not sure if there’s some adapter for covering the crankshaft spindle.
Hi Ian,
On your bike with the mechanical points, you don’t need to use anything as the camshaft seal will keep the oil in the engine. You can leave the mechanical points mounted, but not connected to the coils if you install the optical-electronic ignition module.
Best.
Brook.