Try taking the air filter off,start the engine and give it a "few"revs at the same time close the carburettor intake with something and open the throttle to cause a vacuum in the manifold,this often sucks the crap out of the jet. Note- be bloody careful as the v belt is spinning and the possibility of injury is huge.
No responsibility is taken for this method as it is completely out of my control.
grumble ·