CBF1000 Charging problem- advice needed

[truslack]

I am trying to help a friend diagnose a charging problem on a CBF (I have never worked on these bikes before). The stator coils burnt out a couple of months ago, this was then rewound by West Country Windings, refitted to the bike and it charged perfectly at 14.6v... for 2 weeks. The bike then stopped charging (again) - west country have tested the stator, as have I, and it tests perfectly. We have fitted 3 different regulator/rectifiers but the problem still remains - with a multimeter across the battery terminals, the voltage slowly creeps up to 13.5v, then instantly drops back down to 12.3, this repeats.

Can anyone advise me where to look now? As I am completely at a loss!
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Current: Suzuki RG 125 Gamma, Honda H100, Triumph Tiger 800XC, Suzuki SV650 (minitwin)

[sickpup]

Starter relay.

[truslack]

Bypassed the starter relay with some fly leads, still the same. The voltage is dropping as the fan or the headlights come on, so I believe the alternator is providing the right voltage, but struggles under load, this happens regardless of the battery or the regulator fitted (swapped both out) would I be right in thinking this points to the stator coils? They test fine at 1.1ohms between pairs of yellow wires.
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Current: Suzuki RG 125 Gamma, Honda H100, Triumph Tiger 800XC, Suzuki SV650 (minitwin)

[hmmmnz]

some times, the magnets in the fly wheel can reverse there polarity,
or stop being a magnet altogether,

if the stator is testing out fine, chances are it is fine,
and you have gone through the reg/rec then the only thing left can be the flywheel/rotor

time to change that
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[truslack]

It's definitely still magnetic, screwdriver sticks strongly. Would reversed polarity allow it to generate at all? The stator was rewound by west country 2 weeks before it stopped charging (again).
____________________
Current: Suzuki RG 125 Gamma, Honda H100, Triumph Tiger 800XC, Suzuki SV650 (minitwin)

[hmmmnz]

there is more than 1 magnet in a flywheel (depending on the fly wheel) and if you have tested the windings, the cabling from the stator to the reg/rec , the reg/rec it self, and the cabling from it to the battery and main earth, then the only thing left is the fly wheel

if i were you i would isolate the charging system from the rest of the electrics, then run the bike on constant loss and see if you get any different results,

check the output voltage from the stator at the stator, then again at the reg/rec then the output from the reg/rec and then at the end of the cables (battery end)
would be handy if you has a insulation resistance tester so you could make absolutly sure the power isn't leaking out somewhere in the cables


when checking the voltage at the stator check both coil to earth and coil to coil, its normally set up as a star type windings so will give you a considerably higher voltage

(like the difference in your house etc, 230v to earth/neutral, or 400v between phases)
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[truslack]

[finpos]

Appreciate you are juggling batteries (the bikes and an external one?) - are you always removing one entirely from the circuit or are they in parallel?

f.

[truslack]

[finpos]

Bit of a mystery, then. May help to look for losses in the wiring - i.e. Measure at the regulator output and not the battery terminals.

F.