Rough running

Hi all,
My 98 blade (carbs) has developed a small problem. In first gear at low revs, low speed it has started to run rough. It's very slight but noticeable. It's hard to explain but it feels like the throttle is being chopped very slightly and repeatedly, even though I'm holding it steady. The bike feels like it's making tiny surges in power.
It seems to smooth out when the speed or revs are higher or I'm in a higher gear but maybe the issue is being masked.
I had a problem with the bike dying on old fuel on its first outing this year but that was remedied by a full tank of fresh fuel and its been filled at least twice since then with no problem.
Has anyone got any suggestions as to what might be causing this?
Thanks

Could be the jets, if youve ran out and sucked some debris into the system, could also be worth checking the fuel filter, sounds like the surges could be fuel getting starved then purging. Redex or a fuel treatment could be worth a go, certainly be my first try and the filter before looking at the carbs.
Hope this helps mate

thanks Wes. Popped out on it today for a quick ride to work and it seemed to be fine, so I'm thinking it might just be crap in the fuel system, or filter. Will give your ideas a go and see if it sorts it out.

If it's not that - check the ignition coils!

red x is not good for carbs, if you have ever stripped carbs after someone has run red x through they you can find red dust like stuff. its not good. a strip down and clean is the best and only option.

loved red x... back in the day in mopeds (1970's) but then jets had holes you could drive through:)