I have a skyhawk GT2B-48cc engine and have tried everything to get it to run rite all bolts a screws tight on carb to manifold and bolts on manifold tight but while running i have to constantly adjust the handle bar mounted choke lever to get it to take the throtle and pick up speed and then when you pull in the clutch it cuts of until I put the choke back to a different position and let the clutch back out to get it running again ,the motor has about ahour on it help please !!