Need some help please. I've just fitted a 72cc kit to my 50cc Milano. I've set up the cam timing by aligning the marks on the cam gear with the top of the engine case with the stator flywheel set at T. The valve clearance are set up with 0.004". I've not changed the main jet from the 78 fitted as standard in the PD18J carb. Issue : when I go past 1/2 throttle up to full throttle the revs do not increase much and the revs start to fluctuate. Can anyone advise if this is a jetting, timing or CDI issue.
