Previous owner replaced diaphragm/piston but didn’t seat it properly so it was holed. Replaced with HD part (only one available at short notice) and it runs way better. I did notice the choke cable seems too long and sticks in the off position too. Looks like the cable has been replaced at some point so I’m assuming maybe it’s the wrong cable. May be worth ordering a genuine one to cure that.
Bar riser bushes maybe the next job. Are the cheap ones ok? Or are they something where the more you pay - the more noticeable the difference.
Thank you all for your input - it makes working on it less worrying 😊