Diesel motorcycle rev. counter

For the Royal Enfield diesel motorcycle project, I wanted a 4000 rpm rev. counter. I found a KUS rev. counter that has a signal scaling button on the rear side:

The diesel engine is a Ruggerini MD151 that has a flying wheel with a 2 phase generator output. A piece of electronic did the job to interface the generator output to the input of the revolution counter:

The PCB layout looks like this:

As of June 2017 I have made a smaller PCB design, it loooks like this, size is 21×23 mm:

A road trip shows the diesel rev. counter in action: