The lights on my bike went bright and blew, so i replaced the rectifier as advised by a friend.

What a job that was as it was siezed to the bolts,

And now the battery will not stay charged and it is a new battery,The voltage drops when the revs go up and at tick over it increases

to 13 volts.

Any suggestions of any other possible causes.

they will be appriciated Thanks

http://www.electrexworld.co.uk/acatalog/Troubleshooting-3P-PMG-&-RR.pdf

this will give you step by step procedure for checking battery, reg / rect.

(easier to post a link than write it all)

Thank you for the link,

I now have a guide to follow.