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Breakdown on tuono. Bike started missing at about 5000rpm, thought it was a fuel problem, then thought I'd better ride it steadily home. Cut out while turning round. Failed to turn over then realised only about 10V on dash. Fortunately near a hill and managed to jump start it. Only managed a mile before cutting out again. Breakdown truck to home. Battery charged, bike starts and runs but does not appear to be recieving any charging. Brown connector seems OK. Fuses OK. Stator check seems ok. Rectifier check ok. Will check wire integrity to battery next but wondering what the problem is?
Any idea's what checks to do next, links to helpful diagnostic info?
Thanks.

I think I'll be getting on the Falco untill I find the problem.

My favourite - electrical problems...

You say the battery is charged OK - what voltage is it holding once it's been off the charger for a while? From what you say, the finger of suspicion would point to the reg/rec not doing its job. What you experienced sounds exactly like what happened to me on my old VFR some years back. Only other thing I could think of would be the earth wire from battery to engine has come loose or is badly corroded.

I'm thinking along the same lines as Mango, if the battery is OK, then look at all your earth points including the rec/reg.
When you shut the bike off check the voltage and then re check several hours later to see if you have a short to earth

Ok, thanks for that, I'll Take the battery off the optimate and check the voltage tomorrow and the earth points. I was also thinking I would try swopping the rectifier off the falco and see if that makes a difference.

With the crockadile clips from your tester connected to your battery terminals, check the voltage when the engine is running and increase the revs slowly to see if the voltage rises on the meter?

This is the best way to check your charging system.

I know there is a volt meter on the dash, but I would do the test this way for an accurate reading.

Hi, thanks for the advice. The meter reading at the battery at 4000rpm was only 12.4V. Re-checked the stator only putting out about 5volts at the brown connector, I think the stator is cooked. Will have to dismantle and replace. Apparently common fault on tuono's. Will have to order parts or have stator rewound.
Still lucky enough to have the Falco to play on until its fixed.

You should be getting a reading of around 14 v so there's your problem

fatboy wrote:You should be getting a reading of around 14 v so there's your problem

Agreed. 5v seems impossibly low for alternator ouput. Did you test all three yellow wires/connectors at 4000rpm with no load? All should read 60v or more for correct operation.

Hi, at last new stator arrived and fitted. unfortunately new regulator has yet to arrive. I had previously tested the old one and all seemed ok, so re-fitted and everything as it should be, 14.3V at the battery at tick over going to 14.5V at 4000rpm, short test run to check for oil leaks and kept an eye on the on dash voltmeter, or at least I would have done but it would appear that its only accessible on the tuono when stationary.
Tips I've learnt. Feeding the wire through the V, much patience required , tie some strong string to the old cable when you pull it out ready to pull the new cable through and dont forget to remove the cable tie on the right side, my stator cable was fastened to various other wiring.
Use studs to relocate the cover, makes replacement really easy, keep your finger out of the way as the magnet pulls the stator into position.
Happy days, back on the road.