hi

could anyone tell me why my batterie goes flat when bike is running

someone ran over it

rectifier regulator or wiring going to it, put a voltage tester on the battery with it reving about 4000 revs, it should read 13 to 14 volts. if its still 12 volts then check the wireing to the reg/rec. chris

rectifier regulator or wiring going to it, put a voltage tester on the battery with it reving about 4000 revs, it should read 13 to 14 volts. if its still 12 volts then check the wireing to the reg/rec. chris

chris have checked wires from alternator and thay all seam to go to earth did a conti test on wires

As Chris66 was saying !

Turn on the ignition

Put a voltmeter on the plus and minus on the battery,,,,,,,,,,,battery fully charged. It should read 12volts

Now start the bike and reve it up to arround 4000 rpm and hold it there, the battery now should read 13 to 14 volts.

If it doesnt then your bike isnt charging the battery shile its running.

Check the regulator / rectifier,,,,,,,,it sounds like its fried.

Reg/Rec or alternator, check the windings to the alternator and makes sure they are putting out an AC voltage, should be around 60v@5000rpm, if they are all good then its your reg/rec