Please be more detailed about your condition so maybe we can help. What color smoke is it? White, black, blue, blueish black? Does is smoke under load or and at idle. Is the choke fully disengaged when the cable is pushed in? Does it use oil? What kind of oil are you running in it? Have you pulled the spark plugs to check firing condition? Plugs will tell you a lot about how the engine is running. The insulator should be a slight brown color with very little soot on the thread walls. If they are black powdery then it is burning rich and or ignition is weak. Thick black residue would indicate some oil is being burned. Gray insulator would indicate high speed glazing and or running to lean or plug heat range is too low.