Man, i've had a GS since 2008 and it did produce this sound when i was using 20w-50 but has vanished when i started using 5w-50... the fault doesnt lie with the rear drum padding as the the khattak (sorry ppl from Kohat ) sound originates from the gear box and has a jerk to it too.
The tik tik tik sound is normal as you might have bought a new byk and this sound is normal during the running as the head, piston and the rest assembly is getting used to the thrashing... I blv this tik tik tik sound happens more when you push the throttle to its limits and then switch off the byk n lets it cool??? if yes then it's natural and nothing to worry if not get it checked
Well stuff lyk this happens, when you live in this country and buy products made of as careless a workman as is evident... so dnt stress it