Hi guys, my 1979 xs250 is running rich,sooty plugs,should i try adjusting ,the mixture screw,the manuel says 1 to 2 turns out,can i try bringing them out a bit more,what do you think.

checked your air filter for flow?

the mix screw turned out richens the mix. when did you last check ignition timing and checked contact gap/dwell?

Have you checked the usual, filter etc, choke not sticking, how much town work do you do. Last time serviced?

Bikes don't usually go rich, there is normally a reason.

Has it only just started doing this? Generally once the mixture is set it gets left alone, hence why you hear so many stories of air screws in carbs getting stuck.

Is the air filter clean?

Look at that 3 replies quick fire lol