Starting to get a few quirks sorted on the new bike (87). One that has got me a little stumped though is the choke lever, it moves very freely, it does open the choke, have checked that. But it returns to about 1/4 open if you don't hold it at full choke. It's not such a drama, but I do like to start the bike and leave it idling whilst I put on my gloves and helmet, which I can't do at the moment as I have to have once hand on the choke all the time.

Any ideas, has this happened to anyone else before?

 

Frayed cable or return spring one turn too many after a rebuild??

 

Yup, probably the return spring too tight, as Blue says.
Fraying would make it hard to adjust probably both ways..........

 

Try to adjust the carburetor side so that you have extra travel left in the choke cable. This way, you have some travel left when pushing the choke lever all the way. If this doesn't work, then the problem might be in the cable.