Hi all,
Started playing with the “home dyno” software. If you don’t know it, the idea is you take a audio recording using a signal from the engine that represents an full cycle. Then feed the audio into the home dyne software and it calculates the duration between the pulses. Given the variables of the bike it can spit out a Dyno graph.

Ok, so when out on the road and made some recordings, came back and feed it into my audio editing software.
The signal I am tapping from the engine is the TDC pickup on the alternator which feeds into the TCI.

I was hoping someone could have a look at the picture of the signal and tell me why every forth pulse is different?

I think you've got a rogue red circle round it

If you have a look at the flywheel there is 4 raised parts that line up with the pick up. They are all the same size apart from one which is why every fourth pulse is different.