Hi everyone I am sorry if this has been done a million times but I am confused with what's wrong with the bike I have just got off a friend.
I know before I got the bike my friend had issues with the bike blowing fuses and bulbs so he got a new battery and a new larger regulator rectifier from ebay which after fitting he thought he had fixed the problem, he only used the bike a bit and then sold it to me.
The problems I am having is that I have fully charged the battery twice now with the bike not charging up the battery itself, last night I had to jump start the bike but if I turned the lights on or even press the brake light on the bike would die. I did have a issue ones where the bike wouldn't start after I put some petrol in but started the next day.
I have now fully charged the battery and the bike seams fine, but I need a bike which I can safely use as my commuter bike.
Any help or suggestions would be very much appreciated.
Regards

Sounds like your genny may be fecked. Have a word with geoff33 i am sure he will have a spare for sale.

You may well need a new genny, reg/rec and battery.

well it has just had a new reg and battery so i guess it must be the generator, is this a easy job to replace and would anyone have a working one for sale?

Before you start the task of replacing the alternator why not try a couple of simple checks. Take a multimeter and check that resistance and output voltage from the alternator by unplugging the connector at the rect/reg and connecting the multimeter between the three yellow wires, a-b, b-c and c-a. Resistance should be about 1 ohm. Also measure resistance between any of the yellow leads and the bike frame. Resistance should be infinite.

If you do not get a satisfactory resistance reading between the three yellow leads, then I would check the alternator connector located under the carbs between the V. This connect, along with others in the charging system, has a habit of failing.

If resistance readings are ok, then measure the AC voltage between the yellow leads, should be 50 volts or better at 50000 rpm.

had similar problem with cheap jap reg/rect was charging with lights off but not when lights on just check this

I just checked the bat and got like 12.95 volts from the bat right after coming off the charger, when i turned on the bike and revved it the current volts didn't go up but went down a little, I then unplugged the rectifier and tried to check the readings from 3 yellow cables, i didn't get no reading from any of them. so would that mean that the alternator is fudged?

There is an alternator wiring connector located in the V under the carbs that can fail, plastic melts and wire break-off. I would check that before replacing the alternator.

How do I get to this, do I have to take off the petrol tank and is this a easy job?

You need to remove the lower fairing on the left or right side and follow the wiring as it comes from the alternator. At a point about midway across the top of the crankcase you will meet a connector.