749R Wierdness
 

Just took my 749R trackbike out to get a daylight MOT and then to get fuel. Everything was running fine on way to MOT (2 miles in town), at MOT (which it passed with one comment: "exhaust noisy"...ahem!), then rode approx 3 miles to fuel station.
Put fuel in and the went to start it and it just went "click" and the EOBD orange light illuminated. Voltage was reading approx 12.0V. Couldn't bump start it with help of passing Vauxhall Corsa geezers ("cor mate, look at that tyre on yer bike...did you do that on the roundabout??") so I had to push it home in the baking sun.

Now at home - charged battery for 30 mins. Starts fine again. No orange light. Revved it to 5000rpm and voltage output was about 14.5V so the charging circuit seems fine. Idle voltage (doesn't idle below 2500rpm due to Supersport cams etc) was around 13.5V.
Let it warm up until the fans came on to see if it was something getting hot and breaking down - water temp got up to 102degC with both fans kicking in at about 100 and all was fine. Turned it off, started it up again - all fine. Voltages still good.

Any ideas????

Got a Trackday on Monday so we'll see how it goes there.
Gotta LOVE these fickle Italian machines eh?

R X

Sounds like a dodgy connection on the charging system, my first suspect would be the fuse, i'd replace it just to eliminate it

There's a big regulator fuse - is that the one you mean?

Yes the Maxi fuse as they are known if its like a giant Blade fuse, its only job is to protect from a regulator/Rectifier failure so the only thing passing through it is the charging current on its way to the battery

Update:
Despite being charged up on Saturday, bike wouldn't start on Sunday morning after the above posting.

Had a serious think and realised that since my trickle charger had stopped working a couple of months ago, I had been using a car charger to charge the battery.....yes, I know...how dumb is that!
Nipped to bike shop and bought a new battery and a new trickle charger. While I was out I also bought a Halfords earth lead to slave between -ve terminal and engine (leaving original in place) and new maxi fuse.

All went well at Brands on Monday - bike started no probs and lasted all day just fine. Clocked 13.9V whilst exiting Clearways...this is my new measure of track success!!

Moral: Don't eff about with car chargers, they fry your battery. Cost me 95 quid to learn this obvious fact!!

Hopefully that's it all sorted.

R

Battery.

Yup, battery.