I changed a CHT probe yesterday and ran the engine. All was well. Today I cowled the plane up and went to fly. Tach is inop. Reads zero and does not move. Both mags work fine. I have the ignition booster installed so when I check the left mag the tach goes to zero normally (well shows about 10 rpm). I looked for loose or broken wires and everything seems fine. I assume the tach sensor is the small three wire unit at the top of the flywheel.
I am guessing that you are taking you tacho signal from the coils somehow? Can you attach a picture of this tach sender unit, as I don't think I am understanding properly?
@jabiru-support Away from the airplane. Will respond with photos asap.