Ok well I think this might have something to do with it being hard to start sometimes. Today it started stuttering again, when you plant the throttle it takes ages to get up there. Last week I bunged some carb cleaner down it and it went away and ran really well. I've tried it again and this time it hasn't solved it. When I took the air pipe off the top of the carb, when I press down the throttle linkage there should be a steady stream of petrol coming out of the main jet brass looking thing yes? With the engine off this should still last a few seconds? Well mine doesn't anymore. It'll split abit of fuel out and then stop? Have I just invented this or is that the issue I'm looking for and if so, what could it be?
cheers

Wip the pipe of the carb and crank to make sure pumps working then I'd strip carb of 30min job, clean all jets out and re assamble. Could be some craps gone through

Are you taking about the accelerator jet, looks like a little arm sticking out into the choke and sprays fuel downwards from the end? Should do so for a couple of seconds as the throttle is opened.

Or are you looking at the 'air correcter jets' located between the two chokes? then they don't visibly do anything.

Note, by 'choke' I mean the 2 big holes the air passes through, not the cold starting aid.

Yep, the accelerator jet. Sorry, reading that explanation back, my general lack of mechanical knowledge/terms probably doesn't help.

Well if the accelerator jet isn't squirting it might affect hot starting(with the throttle pedal down), but probably not when cold(no throttle). Check the external linkage is operating the arm on the accelerator pump, try operating the arm directly by hand, if still nothing check the diaphragm.

Cheers Joolz.. Think I've found the problem I've been looking for by the sounds of it.