If it puffs black smoke, two accelerator pumps try moving the accelerator pump arms to the lowest hole on the arm, shortest stroke As far as burning and stinking at idle try leaning,with the motor running, screwing them in,the ile mixure screws very slowly, 1/4 turn each on all four and wait for a while for the unburnt fuel in the intake manifold and exhaust system to clear out and then try again until it is lean enough to not stink at idle BTW, make sure first that the motor is running on the idle circuit only, check the primary throttle blades to see if they are opened enough to be in the transition slots instead of below them If they are, close them down so they aren't running on the transition circuit and adjust again, look at the metering rod pistons again also