Motorcycle Repair: 1980 CBX 1000Z Charging problem, friction plates, driven plate

Question
Hi - I have a huge problem with my bike.  I found it to have stopped charging.  Its had new brushes in the alternator, the alternator has been to a specialist twice - they say there is nothing wrong with it.  The voltage regulator and rectifier have been tried on another CBX and are working fine.  I'm not sure what  else it can be.  Can you suggest anything to try next.
Many thanks,
Kind Regards,
Nick.

Answer
Hi Nick, the problem is likely with the drive.  There are two friction plates which provide the drive to the alternator.  The spring behind the driving plate can get hot, and relaxes.  There are two washers, one fiber washer and one steel washer which go between the driving plate and the spring.  The spring sits on a special washer which goes on the jackshaft first.  Also inspect the driven plate, it should have a thick edge to it, and the way to ensure that the drive is positive, check that the spring is starting to push against the plates when the alternator is still 7mm aways from the fully home position on the engine.  Also it helps if the battery is fully charged, as the load on the alternator is much lower when the battery is charged.  If you are a member of the ICOA (www.cbxclub.com) then the charging issues are described in detail.  Let me know what the alternator clutch looks like.  

Good luck,  Jan