If you are getting black smoke you are right the carb is rich. What Stuart was refering to on the gasket is the carb has a vacuum hole in the bottom that must have a passage to the intake manifold. If there is not a cuttaway in the gasket or it is not lined up it will cause this problem. Make shure the power valve piston goes up & down & the ball with a spring behind it seals the hole. Take a look at the spark plugs. If they are carboned up it is a good indication it is too rich & compounds the problem. You may have to clean them. The monojet is a good carb.
