Charging problems

my bike died at work earlier this week, jump started it and now found im having charging problems heres the what the multimeter says:

At battery:
no engine lights on/off :12V
At idle lights off: 14V
lights on: 13.5V
At 5K lights off: 14V
lights on: 13.5

The yellow wires before the reg/rec:
at Idle lights off: 5V
lights on: 9/10V
At 5K lights off: 5V
lights on: 9-12V

Im guessing i need a new alternator, possibly reg/rec and possibly new battery, so i can get hold of parts from a pointy k4/k5 would they be a straight swap? or do i need curvy parts if so anyone got what i need

Thanks Sunshine

[yorkie_chris]

No don't use pointy stator, wrong pickup for ECU.
You could use reg rec, but plugs are different.

Are those readings from yellow wires a) with alternator disconnected from reg rec and b) with the multimeter set to read AC Volts?

still connected and multimeter set to ac

disconnected the reg the reading was over 50Vac with lights on and off, i cant get more accurate than that until i get my other meter back from a mate

Regulator sound fine. at volts 12 volts battery is low. testing yellow wires should be on ac and between 2 yellows. Faulty battery is my conclusion.

so time to look up battery man.

I have tested between 2 yellow wires with the reg disconnected, over 50Vac with lights on/off at idle and 5K so reg/rec and alternator both fine then? im cheap and dont want to part with cash if not needed, im guessing 11years for a battery is pushing the limits abit then?

A regulator in ideal state would give around 14.4 volts. If you are charging a low battery this will fall. Also a high load especially at lower revs will also make this fall. So your readings don't look bad at all. What you need is the battery voltage whist cranking. A battery charged and in good condition should give 13 ish volts (ideal would be 14 but we are not in ideal state) When cranking drop to about 12Volts or very slightly under. If it drops below 10-11Volts then suspect a battery. Of course a faulty starter could draw a large current which will make the battery voltage drop. To double check, Check the battery voltage, then put all lights on and remeasure, it should still be around 12volts or very near. If it drops significantly, then this will be the most likely candidate for renewal. Regards Dave

[yorkie_chris]

Yeah I agree, battery not holding charge.

AHHH FORGOT check out the main battery terminals and the connection to the starter, and main earth lead bad connection will cause same problem, sorry too blinkered in my reply. Also check battery fluid level. (still think its a battery though)

yes i have checked connections, the starter is connected fine too, which part of the main earth lead? where it connects to battery thats fine, the fluid level was fine at last look, so im guess throw a new battery on and seeing if it dies again?

The wire from the -ve side of the battery connects to the main earthing point on the engine, sorry don't know where that is on the pointy, just follow the wire, its normally short and obvious. Then save up for the battery