My briggs and stratton lawnmower was running great then started spluttering. Cleaned air filter changed spark plug still the same. Spark plug goes a sootie black colour in 30 secs. Also its pulsing badly with a bit of black smoke. Any help welcome . Model no: 10d902 code:02022254 type:0141b1 if that helps

Sounds like it's running rich. Is the choke sticking?

Played about with the choke seems to be fine. Tried holding the govener on full made no difference as soonb as you let go it continues to fluctulate back and four.

Have you tried to adjust the fuel mixture. Turn all way in but not tight, just to wher it seats,then back out 1 1/2 tun

I'm a total novice at this sort of thing where do I find the adjustment screw

On the side of carb.Will be a screw with a spring on it

Adjust Your Carb.