PHBH carb leak
I agree with Mrnice , worth checking . Av a look at this - ( Fuel supply system - 3.2.2 ) .
http://members.iinet.net.au/~petercusac ... o_3_2.html
Also check/clean or replace the float needle , should have a red tip !

To check if the float needle is working correctly , blow down yer banjo

Good luck !
Cheers.
P.N.D.S.C.