Honda atc125 dirty smoke after fitting new piston rings

[digaholedumper]

Just picked a atc125 up as a none runner, managed to get it running & serious lack of power & lots of smoke, no air filter fitted by last owner so its likley dusted. So got to work & removed the barrel & she is allready 5mm over size, managed to clean the bore up with glaze bssting tool & find a set of rings to suit, fitted these & re-seated the valves, new gaskets & valve stem seals. started it & rode it for the 1st time today & she is 100% better & starts real nice with no choke, when you rev it repeaatedly there is a fair bit of dirty grey smoke & it wont tick over reliably, checked ignition timeing & messed about with that but no improvement, would I be wasting my time fitting a new aftermarket carb to try improve things ? Would be greatful for any sugestions.