Fixed it!!
Missing has gone 
The replacement carb gasket and diaphram seems to have fixed it 
I reckon the old diaphram was letting too much petrol in.....because when i started it before, it used to smoke (white) quite badly for about 10secs until it started to warm up.......doesnt do that now 
Tho i was running it without airfilter.....would that make the difference 
A question tho.....I probably didn't need a new air filter....but i got one anyway....what sort of oil are you suppose to soak it in? Will Vx 10-40 do the job?
Yes, running without the air filter makes a big difference on such things.
Further more, many of them pump the fuel using a flappy rubber diaphram which is actuated by the vac pulse between the carb and the air filter.....no air filter, no pulse.
Others use the pulse of pressure from the crank case.
Then others use a gravity feed.