Thanks for all your suggestions, I can strip the carb down blind folded I've done it that many times.
To answer the points in turn.
It doesn't specifically happen after washing though the bike is a pig to start after a wash. If you leave it dry out it starts and runs fine assuming it was running ok before the wash. I do have short vent hoses fitted to stop water getting in a assist blowing out the carb when cleaning.
The failing stator is interesting. I might try measuring the resisitance when the bike is running ok and when it is playing up. Does anyone have any resistances for a Leonelli stator?
I haven't looked at the O ring on top of the carb. Will check this.
The O ring on the choke jet does look like its been chafed where it seats in the float bowl. I'll get this replaced and chamfer the hole.
The slide is seating properly and the cable is correctly routed etc. Its running so lean it won't tick over due to lack of fuel if you give a little choke it it will run at low revs.
The float height is correct and the fuel filter is clean.
Could send some more details of the vent hose system?
I am going to start with the O rings as their the cheapest, knowing my luck it be the stator.
Thanks again, any other suggestions would be appreciated.
Scraggydog