F650GS cut out and failure to restart

Bike is F650GS MY 2012. I have had some issues in the past year or so with the starting system. To cut a long story short, there appeared to be some sort of wiring issue problem which I eventually resolved by running heavy duty cables from battery positive to starter relay, from relay to starter, and earth cables from starter to battery neg terminal and also neg terminal to frame.
A couple of weeks ago the bike just died. Tried to re start while still rolling with clutch lever in, no go. When stopped, pressing starter button just gives a click from starter relay as if battery flat. Instruments and all other electrics seem fine but no start.
Further investigation shows that battery ok. As a second check, connected jump leads to sons car, and no change, just a click from relay.
Kill switch appears to work as it should, clutch switch likewise. Haven't been able to get to the side stand switch connector yet but if bike is in neutral then even if it were faulty it should not prevent starting if in neutral, am I correct here?
It seems to me that it is unlikely that the cutting out and the non starting issues are unrelated and just happened to crop up at the same time. I am however at a loss to know what to do next.
Any advice gratefully received!

I'm not so sure about the issues being related. However, I'd start with a scan using dealer level diagnostic equipment. I'm suggesting this because my G650 developed a stalling and hot starting problem. A GS-911 scan revealed no fault codes.

My local indy who is an ex Motorrad head tech found what he described as "a very unusual fault code" which was intermittent failure of the crankshaft position sensor.

Thinking about it logically, if that was the case, I've no idea how the engine kept running. I've not had a chance to ride the bike since he replaced the sensor but I trust it's going start as it should and potentially perform a bit better.

Thanks Schtum, you may be right. I have a GS911 and there are no fault codes present. The difficulty is that if I want to get the bike to a dealer at the moment that means van or trailer, neither of which I have.

Had same problem some time ago. The large loom which runs round the steering head and the cylinder barrel/head is prone to chafe and earth. It's well known issue. Just need to dig in there and inspect v closely

I have been thinking about that but there won't be much that moves as the ignition switch is frame mounted. What did you find with yours?

You don't mention the bike's age/mileage/service history. Neither do we know the battery age nor whether it has ever been fully discharged for any reason.

So, before embarking on any potentially lengthy search campaign, it's always best to get the battery tested - most suppliers can run a condition check for a few £s, refundable if you need a replacement

Then that strange rewire need could suggest some direction, so initially I'm thinking starter relay, or starter brush box (worn or jammed brushes).

If you have the neutral light, you should be able to give the command to start, unaffected by clutch switch conditions.

However, the familiar problem areas are EWS, fuel pump, tank breather & the ignition switch itself (usually water ingress), so bear these in mind. The occasional cutting out as you roll up to a junction seems to afflict some F-twins & you will come across many observations on the subject - I reckon these engines run so lean when the throttle is feathered that it seems almost inevitable without a quick blip on the down change to wake things up.

Anyway, good luck tracking down the problem.

seahorse said:

I have been thinking about that but there won't be much that moves as the ignition switch is frame mounted. What did you find with yours?

Click to expand...

Afraid to say it was time consuming. The vibration over thousands of kms had caused the loom to wear through against the cylinder head. The insulation had only worn through in a small place but it allowed a wire to earth. It might be possible to check the wires from the ignition switch to earth with a meter but if you find a leak you still have to go hunting the loom for it and re-insulate it. Good luck.

That certainly sounds worth exploring. The bike has done 76k. Air box and battery out then.