I have a 1987 Mitsubishi Mighty Max 2.6 L 4Cyl w/ Carburetor, It has recently been running roughly and my mechanic said he thought it was the carburetor. I rebuilt the carb, and the symptoms decreased, but did not go away. The engine runs roughly at times (and black soot come out the tailpipe). About 1/3 times when I turn the key off, the engine doesn't completely shut off. I have replaced the plugs, wires, cap & rotor, and rebuilt the carb. What else can I look for?
You may think that you rebuilt the carb but simply changing gaskets is not rebuilding. It requires extensive set-up and testing of the housing to eliminate all the issues. Replacing it with a factory reman is about the only way to resolve the problem.