instated Raw Racer 100 (YD 100 style motor) and i am getting close to finishing the break in. I love the motor but it wont idle. If i turn the idle up, it will idle, but its way to fast. If I turn it down it will idle for a bit the drop rpms till it stalls it did this on both of my carbs. when the engine is cold, it idles and as it warms up the idle gets higher and when i turn it down it stalls. I am jetted a little rich cause the plug looks fine and at full throttle it four strokes unless I gradually increase the throttle. I know its avacuum leak but i put a new intake gasket on, used permatex copper gasket spray on all surfaces and installed brand new o ring. where else could it be coming from? motor has only 40 miles on it. i also tightened all the cylinder bolts.