Petrol problem

[paulmattb]

Hi can anyone advise,I've got a px 125 and I'm having trouble starting,it started Saturday but cut out and wouldn't go again,checked spark and that's fine,no petrol coming through,so I blowed down pipe and it seemed to work until tonight,it started and cut out again,blowed down the pipe but nothing this time,could it be a faulty tap?
Cheers