Hi all. Fueled up ready to ride. Turned fuel on, pulled out choke then noticed small drip of fuel coming from fuel switch. Turned it off and it stopped. Turned it to reserve and it was ok. Turned it on and drip starts. Has anyone ever stripped one down? Is it o rings inside that have perished. Seen u can buy new fuel switches for £15 but I have o rings of every size in my possession.