One more think the fan is not on all the time

 

Just for ****s and giggles: the green ground wire on the RR is making good contact? If not, you could try a slight mod like this one https://cbrforum.com/m_26983/tm.htm. You could also doa continuity test on the red battery charging wire coming out of the RR to make sure there is no breakdown in the wire heading to the battery.

 

no starter fault when hot, it will start almost on a flat bat first kick, thx for yr question and fan only comes on when hot, its the low rpm trafic lights that is the problem

 

u think like me, i was going to run another wire straight from the voltage reg to the battery to eliminate voltage loss and im going to amp test when my ammter arrives, but i dont have much time this week and my birthday this weekend so will be out on the lash, cbr might have to wait a while ! and that link u sent is perfect, time for a good ol tidy up around the earth/plugs wiring dep

 

just wanted to let people know who are interested, i took my bike to a bike shop, had the sparky look at it for 2 hours he said everything i had done was good, that was:
a/
run new high gauge wire from output wire (wr) from regulator straight to bat positive
b/ run new wire from negative bat to RR post.
and check voltage drop via possitive lead on bat+ and negative lead on RR output wire underload. i.e lights, there should be no voltage reading, anything more that 0.2v is to much imo

and do the same with negative system.

so after 2-3 hours he calls me up and says he thinks its the RR, and i was like but u tried one in there before i changed alt, he said there is nothing else to change and maybe the alt/RR had both gone,

i said ok whats the damage, he only charged me £25 and was happy for me to sorce my own RR

so i ordered new RR for £55 and fitted it , and its fixed charging 14.25 volts just off idle, i.e 1200rpm, under load with high beam, is still around 14.00-14.5v just above idle say 1500rpm

so will see how it goes, it was an aftermarket RR but gen honda ones are close to £200
hopefully more happy night riding