Powerdynamo brings new ignition & light 
to your vintage motorcycle



Technical Help



problems with different versions of camshafts in BMW R69, 69S and 68

The camshaft of type R68 ist longer.
For our ignition systems that means a difference in position (hence shape) of the cam-piece which is used to plug the oilseal and (in our cam-triggerd systems 70 80 999) to take the trigger disc.

Most BMW so far for which we delivered our System 70 80 999 or System 70 81 999 had the short cam and assembly of the cam-pieces looks as shown in the picture here.

The standard cam-piece reaches into the oilseal.

And the trigger disc (in modells 70 80 999) is positioned correctly against the sensor as shown here.

In most cases where there was an R68 cam in the engine, the standard cam-piece does not reach into the oilseal. It ands shortly before it.

Here we first made some prolongation of the cam-pieces as shown in photo and later modified entry diameter of the standard piece to allow it to sit lower. See sketch below

But, we have also got cases where the standard cam-piece reaches into the oilseal but the trigger disc if lying beyond the sensor by some 15mm (hence not enabling any ignition pulse)

here solution should be to place a spacer block of 15mm thickness under the sensor.

What is visible in those cases is that the engine housing of the engines concerned looks different in the camshaft area (see photos below)

But why and when do we have those differences? How can one recognise this before ordering? We are sorry to say that presently we do not know the answer to this.

In case of doubt better ask for system 70 81 (crankshaft triggered system), than at least the problem of the trigger disc can not happen.