Z1OwnersClub GB

Help needed please.
I'm trying to sort out those little niggles that come with a build entirely from separate parts. I am using a complete engine and loom from a Unitrak and have a problem with the charging system. I have tested 48volts AC from the generator at 4,000rpm and have tried a reg/rec which I know is good. I only get 12.6 - 12.8 volts at the battery once running. My manual suggests the possibility of weak generator magnets as whilst everything bench tests okay once under load nothing much appears to be happening.
Any tips would be appreciated.

have you got battery voltage at the brown wire when ignition is turned on ?

Battery voltage yes which after standing for a couple of hours is showing 11.9 volts.
I did completely discharge the battery in February thanks to leaving the ignition on.
I have another battery which I will try in the morning.

Hi Chris, a good lead acid type battery should give 2,2 volts per cell ie 13.2 volts with the voltage rise you are seeing would expect a decent reading with good battery though 14.6 v is deal,as a double check wire a multimeter set to dc amps in series with the positive side of battery to show battery is accepting charge.Cheers Paul j

If you completely discharged the battery it will be shot. Wait until your new battery arrives and check again. If it's still low then look a bit deeper.

48 at alt is down a bit as it should be 50 v so probs why ya only gettong 12.9 at batt but should still be emough to keep it going

Hi Steve.
I had a better chance to run it further.

You are probably right because the battery voltage even with lights on remains at 12.9v.
Would the lack of output voltage, even though the manual says 50v is ideal, be down to weak magnets or windings being worn?