old CG125 problems

Moto2

I wouldn't upgrade it

Go through the fundamentals and get it running right

enfield_freddy

jet sizes would be a good start? is this the std carb fitted to them , if so which model of cg , steve at motocarb in skelmerdale is only 1/2 hra way , and could supply new jets/needle etc , but requires the numbers

Moto2

Those carbs all seemed to have the same jets, I can't really see how they could have 'broken'
From memory, the main is 0.78mm but I'd need to look though my manuals to be sure.
Check the float for height and make sure it isn't damaged, check the needle is in the middle groove, check that the sealing on the manifold and airbox rubbers is good.

if all is good, lift the needle one notch and record the results

EDIT: my lad thinks it's a .92

Could be anything but I'll hazard a guess it's got the right one in it.