Right, quick update.
The carburation is sorted (well, almost). Apparently, the good old Japanese like to mess with different size carb needles & needle jets within a 2 year lifespan, I had the wrong combination, hence why the bike wouldn't run right.
Using a magnifying glass showed that I had the wrong needles fitted after I noticed that I had 2 different sizes in my spares pot.
So, with the carbs removed, I fitted the new jets & needles, fired the bike up & went for a short ride. She's running 99% better, but still runs on a little when I come to a stop, so just need to adjust the mixture slightly & she should be right