Daz,
That sounds similar to the problem I was having before I put on the new coils.
I only have about 300 miles on them & the problem has gone away.
But I still think I might have a CDI going bad.
That is just based on what I am reading on different forums.
I did try a new CDI & I still had the problem though not as bad.
I am now running the original CDI with new coils & so far it is alright.
I just put some fresh Dino oil in,filled the tank with gas & added stabil.
Went for a 15 mile ride.
The bike ran great.
It is now covered in the Garage for a while with a trickle charger on it.
Wish I had a good answer for you.
I am going to have some Coronas now.
You got me hooked on them.