I have a 1989 dodge ram mini pickup. It has a 2.6l 4 cylinder engine when i start it ,it runs rough and when i step on the gas the carb makes a crack noise and sometime a mist of fuel sprays out the top. The timing is fine and the valve adjustment is ok . can the carb need to be rebuilt? and after i shut the truck off i have a small amount of smoke coming out of the carb. any help woud be welcomed. Thanks Dan