If you dont have a timing light, put 2 marks on the dizzy and the mount part (that doesnt move with it) so you know were to put it back to if it doesnt help, but fiddle around (little movements are bigger than ya think) with the dizzy and move it each way and drive it, see if it helps, if it gets better, then turn it more the same way and see what happens, only takes 5 mins and could fix the problem easy as, if it doesnt help turn it the opposite way past your marks, if that doesnt help, then compression is too high for the fuel your using I'd say