Had a play around with the two petcocks, only got a photo of one. Here's a part of the rebuild that you shouldn't cut corners or you will either be left stranded on the side of the road or worse still have fuel running all over your hot engine
New genuine Yamaha O ring, base gasket and fibre washers.
I've replated the front plate and vapour blasted the body and tap.

and a different view.








