1984 gl l200 goldwing starts to smoke aft...

If smoke is blue, then it is oil getting into the combustion chamber(s). If it is black, then it is excessive fuel use. If oil problem, then either bad/stuck rings on the pistons, or oil past the valve stems. Check the crankcase venting system. Use 'high mileage' oil. Try a 'ring-free' oil additive. Check for proper oil drain-back from valve covers. If black-smoke problem, clean or replace the air filter.

The rings need replaced