erratic rpm

[jonz feroza]

hey..my little feroza overheated a week back and in the process it put little splits in a radiator pipe.got that fixed.now the engine once up to temp,fluctuates in its rpm. eg 90kmh=3000rpm-3500rpm.i have to keep the foot pinned in order to keep the rpm down which is no good.makes for one crappy drive thats for sure.any help much appreciated