Small Engines (Lawn Mowers, etc.): BRIGGS 20 HP TWIN, fuel mixture, carburator

Question
ENGINE WILL ONLY RUN (ACCEPTABLY) AT 1/2 CHOKE. APPEARS TO BE TOO LEAN FUEL MIXTURE. I FIND NO WAY TO ENRICHEN IT. ANY SUGGESTIONS?
THANKS,
DAVE

Answer
 Hello Dave:

 You have the Non-Adjustable Carburator. It Must be Cleaned and Rebuilt. If you are going to try the Rebuild yourself, Send me the Model, Type and Code Numbers Off of the Engine and I May be Able to get a Diagram to Assist you. Hope this Helps. Let me know what Happens, Please.

 Good Luck

 Respectfully

 John