Okay whilst out riding the other day, the above mentioned unit decides it's had enough and burns out (clue was lots of smoke when i stopped). I have a new one on order. When that arrives is there anything I should also check after it is fitted to prevent any further mishaps. I,ve already checked the battery and replaced the fuse that blew. I put my sons fzr600 reg/rec on and started the bike revved it to 3000 rpm before the fuse blew again. The one off my sons bike is also fairly new, so I was wondering if I could have a problem elsewhere.

It sounds like you still have a problem, I would check all the wiring and pull apart all the connections
between the reg/rec and alternator.
Also check the alternator.

New rectifier arrived today. tested the generator for resistance. checked the battery again. attached the reg/rec and pushed the button. Started eventually!!!! god it hates the damp weather. No problems with my bike so thinking my sons new reg/rec is not as it should be. Put all the bodywork back on and posted a few pics. it looks better than when I got her.

I have had loads of long running problems with my reg/rect boiling my batteries etc. I got the manuals out and did the tests and everything seemed ok then my battery boiled.

The only symptom I spotted was badly corroded/burnt connectors near the reg and once at the alternator coil connection. I hard wired these and did the checks (including coil alternator coils).....still ok and boiled another battery I changed and tested a new reg ..and boiled another battery

All this has happened over a couple years so I have just put on a thundercat reg and gonna give that a go. I figure its newer and a bit larger so might handle the heat better.

hth

There`s a little gizmo for testing a charging circuit made by Blue Point it`s an MT130. They`re not made anymore but do come up on ebay - I got one from the US cost about 30 quids