Small Engines (Lawn Mowers, etc.): Adjusting carbuerator on 11hp B&S MTD Riding Mower, air fuel mixture, mtd lawn tractor

Question
I was trying to stop fuel leaking from the carbuerator after engine shut off and managed to mess up the carb.adjustments. This is a mid 1980's 38 inch MTD Lawn Tractor with a one cylinder 11 hp Briggs and Stratton engine. It has two adjustable screws: One on the top and one on the bottom. How should I set them? Any suggestions about fuel leakage from carb. while engine not running?

Answer
 Hello Jim:

Problem 1- Set Both Air/Fuel Mixture Screws 2 Turns Out. Then Override the Governor and Adjust the Bottom Screw (in the carb bowl) as you Rev the Engine. You will Hear the Difference as you Adjust this Screw. Once the Engine is Reving Properly, Allow it to Idle. If idle is Rough, then Adjust the Idle Air/Fuel Mixture Screw Accordingly. Problem 2- The Carburator Float Needle isnt Seating Properly and causing the Problem. I would Install a Cut Off Valve in the Gas Line and Turn Off the Flow to the Carburator each time you are Finished with the Mower. Rebuilding the Carburator May Help for a While, But the Cut Off is a Back up. Check the Gas Tank Cap and Ensure it is Venting Properly. If not Pressure in the Tank will Push the Gas Past the Needle and Cause the Same Problem. Hope this Helps. Let me know what Happens, Please.

 Good Luck

 Respectfully

 John