Hi all,
Thought I would pass this on incase it is of any use to others.
I recently had problems with the petrol tap on my Z650 F4. It is the diaphragm type that is opened by the carb vacuum. Anyway after being an idiot and running out of petrol I found that when I removed the petrol tank fuel was running from the tap when it should not have been. I suspected that I had damaged the diaphragm inside the tap so ordered a new one from Z-Power. Once it arrived I duly changed the thing and thought all was OK. To my surprise when I refilled the tank petrol was still coming out.
I again stripped the petrol tap and started to clean it ultrasonically. I eventually found the problem to be dirt in the small brass connector for the vacuum pipe which was causing the a small rubber non return valve to stick and not let air pressure back in thus holding the tap in an open state. Once I had unscrewd this and cleaned out the inside fuel leak solved.
Hope that this makes sense and that it is of use to others
