MK Indy with 919 fireblade engine.

Went into garage this morning and battery was flat.
Jump started it off my van and gave it a good run. Battery has charged up ok but the ignition stays on, unless I disconnect the battery.
The only thing done recently was to fit a replacement speedo sensor, so I disconnected this and it doesn't make any difference.
Anyone got any ideas why the ignition is stopping on.
As you can probably tell, I'm really bad with electrics. I didn't build the car, so Know very little about the wiring.
Cheers
Tom

Hi Tom,

My first reaction would be knakered rectifier but I don't know a lot about blades.

I'd also avoid using the engine to recharge a flat battery. The charging circuit isn't designed to do that (its only intended to run the cars/bikes electrics and top up the charge used to start) and it puts it under huge load.

adrian

if you get it over to mine, will have a quick look over it.

Cheers for that Adrian.
Welderman, I might pop over to yours tomorrow. Otherwise theres a cheep auto electricians close by.
Tom

hmmmm, bike engine ...... not sure if that makes any difference but thinking about it I would say the ignition switch or the wiring to it and the igntion is the culprit.

the alternator is connected to battery all the time; if the regulator/rectifier is bad,then that can drain the battery.

the igntion switch completes circuit between battery and the ignition, without power, the ignition cannot run and should not be wired directly to the battery/alternator.

Had the car round at weldermans today and discovered that it was the ignition switch at fault. Sorted it now and everything is fine.
Cheer all especially welderman.
PS welderman. The backfire on overrun has gone too, so it was that tube we blocked off.

just glad we got it sorted