need carb help Quantum 7150 150cc
 

OK so I picked up a quantum 7150 that had been setting for a while with bad trans gears which I fixed. having carb issues... the carb will not idle unless I put my hand in front of the carb and barely cover it, it then runs fine. I've went threw the carb many times and cant seem to find the issue, I've replaced the fuel lines, fuel filter, some times it will start and idle then die. I've cleaned the jets, turned the air screw out 2.5 turns as specified in the manual, what am I missing? please help!!

is there something in the carb I have missed?

In front of the carb? Is your hand at that point covering the intake manifold? Sometimes the intake manifold can have a crack in it and therefore cause a vacuum leak.

I'm thinking you might have worn piston rings creating low compression to draw air into the carb. Have you lashed the valves since you bought it? They go out of whack in like 500 miles and create weird problems when out of adjustment.