Could it be the reeds
Turns out it was loads of crap in the carb I have just changed the tank as the pep seal had lifted the sides off and there was chunks of it in the tank the carb filter was full of it and was blocking the fuel at top revs. Seems ok now
If the reeds are damaged you'd struggle to start it unless you have a big hill to bump it down. You'd need to get it spinning at an RPM where the reeds would be mostly open which is pretty much unattainable with a kick starter.