Firestorm drive problem

[robbocop33]

Not had the bike long so just feeling my way round it sorting little niggles.Basically you know if you were driving along at say 30mph and you were in say 5th,6th gear,the transmission would start to clunk wanting to change down a gear?Well thats the sort of sound i get?.
Say im driving along in 3rd gear along behind traffic in a town with a steady throttle,it will clunk then,when i know im in a correct gear for road speed,i just rev through or by instinct,go for a lower gear and it will still do it??
First thing i thought was slack as fk chain,and guess what?,the chain was slack as fk.
Tightened it up no improvement?Bike pulls away from idle perfect,changes gear without problem.pulls cleanly under acceleration etc,it's odd?
Could the clutch do this?Maybe a basket wear problem or something?

[robbocop33]

Good call about the cush drives,always forget about them!Well except for when i was into old 70,s musclebikes.
Fuelling ofcourse might be another thing,i'll be getting around to balancing things when i get the time anyway in due course.Thanks for the replies!