It's gone 'reasonably' but not 100% to plan

The clutch work went well but the blasted crank case now leaks oil BADLY!!
The new gasket is far too thin (I didnt notice) -- about 1/3 of the one that came off... So a redrain and silicon is required to sort. ill probably replace the bolts with studs at the same time.
The expansion chamber and carb mods have made a massive difference .... revs really responsively and sounds great... rides well (sort of LOL)
HOWEVER ..... theres always a however!
The carb will not allow idle/starting unless the choke is on. As soon as the choke is turned off it dies unless i rev past the idle jet position where it runs really well...
I have swapped the idle jet to no avail and am thinking that the idle circuit may be blocked??
Putting my hand over the carb when starting is dry.... untill the choke is on, then its wet
Any ideas guys? The carb is an OKO mikuni copy, straight out of the box (apart from re-jetting to suit what was used by others)
Thanks for any input
GP200 SIL engine
ScootRS series 2 expansion (lovely bit of kit)
OKO carb (30mm I think) -- not so lovely -- but looks nice LOL
Julian