Aye neo you are right, but I decided I would live with it for the time being. As it runs nicely on the move and gets very good mpg I don't think it's running excessively rich. Actually I initially thought it must be running too lean, to get 63 mpg at granny speeds, and 50ish even when blatting aroud the countryside, but it runs really smooth and nice, doesn't get too hot, so I think it's OK.

It's true it doesn't like to sit in traffic jams, but lucky for me I generally don't get stuck in traffic. Back in my moped pizza delivery days you either learned to filter efficiently or didn't get paid; white helmet, white bike, hi-vis and hi-beams help with encouraging people out the way as well