Adjusting Fuel Air Mixture on Lawnmower

I have a 4 OHP Quattro Briggs & Stratton engine on my lawnmower, and it seems to be running rich. (It sort of "gulps" while running, and near the exhaust a black spot develops when the engine is running. ) I was told there should be a fuel adjustment screw near the sparkplug, but I don't see it. Could someone tell me if there is such a screw, and if so, how I can find it.
Thanks,
JD
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Decij wrote:

on lawnmowers and pre pollution control cars the adjustment screw was on the carb. and you would use a screw driver and screw it in all the way gently and then back it up 1 1/2 turns and play with it from there... how does that sound.....
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Jim,
Thanks for your reply. I have a general idea what I am looking for (I used to work on a 66 Pontiac Tempest), but I don't know where to look. I was hoping someone could save me the time of trying to locate the screw.
JD
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Decij rambled on about something in

JD, who made this engine? If it's the widespread Briggs & Stratton, the mixture needle screw used to be on the back side of the carb, behind the bracket connecting the tank to the cylinder head. It's accessible thru a small circular hole, and takes a standard flat screwdriver. <G>
OT BTW, being a car nut, I bet you regret getting rid of that Tempest. <G>
HTH
NOI
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