1150GS - Failed start, tacho indicates 4000rpm - no prime or engine turn

2001 1150GS (single spark)

Not what I needed today or this week!
This is my only transport and as I am moveing out from home this week - not the most convieniet time! normally I would read, research and trouble shoot, but I dont have time / ability at the moment.

Just about to pull away from a friends place, went to start and nothing.

Pressed the start button, a little bit of a crank on the engine and then nothing.
The tacho needle indicates about 4500rpm when turning the key to 'On' position

Nothing happens when I try to start.
Usually the fuel pump will prime with key turn or kill switch indication - nothing.
The engine doesn't even try to turn over - nothing

in 2013 the Hall Effect Sensor system failed - had it rewired with aviation wire and connectors - been fine since.
1 week ago I had to jump start it as it had not run for 3 weeks (I dont have it on a tender). it is my daily transport and doesnt usually have a problem.
The battery is 100 weeks old (I know that because I was looking up something else and know that the battery failed 4 weeks from that event!)

I dont think the battery has failed because a) the engine would try to turn
I am leaning towards the HES because of the tacho indication at 4000rpm, but surely it should still try to crank and do something so I dont actually think it is that

I am thinking something in the load releif relays system.

Please, can I get some solutions and directions.
I do have an 1100S that I can rob parts from if needed - but i'm not going to throw parts at it hoping something will fix it

thanks

It suggests that you could have a fault with either the ignition switch or the kill switch.

When you turn on the ignition do you get lights, horn etc. If so then the ignition switch could be OK.

Which then suggests the kill switch.

With a duff kill switch you will have no fuel pump prime or motronic (provided the side stand and gear selection is configured for the bike to run). And the starter will not operate when you press the start button.

Ian

The load relief relay has nothing to do with the Motronic or the fuel pump prime. It is there simply to cut out all your ancillary electrics when you hit the start button, so that all available power from the battery goes to the starter motor, motronic and fuel pump.

Ideally if your bike is serviceable. To test the load relief relay. When you hit the start button the lights will go out as the starter motor turns.

Ian