... the vacuum tube, it can save 10% -25%, increase power at 20%,reduce emissions at 50% -80%, to ... protect the engine 5, gaining momentum 6, easy increase speedSix characteristics:1, Well-designed, well made2, the ... if the idling speed is slow, need to increase the idling speed of the carburetor, and then ... repair function, it is normal when idling speed increase and then drop immediately.5, Turn the motor ...