Vacuum taps were once state of the art.
The day you upgraded to a bike with one those new-fangled vacuum taps things was a momentous occasion indeed. No more did you fumble with the petrol tap every time you started or switched off the bike. It was nothing short of a miracle!
But like anything, it can go wrong and some people are put off by trying to fix it. A diaphragm and O-rings are pretty much all there is to it, so this is a quick tutorial on how to fix it. Bearing in mind I've actually taken this tap off the tank four times since painting it, to try and get it to work correctly. It's been a pain, but today I think I nailed it.
Also, number two carb needle valve could be leaking slightly and allowing it to flood the cylinder when left a couple of nights. Had the petrol tap switched off correctly it wouldn't have been an issue, but if my brother's sister's aunties' nephew wasn't my second cousin I wouldn't be in this palaver anyway. What?