Small Engines (Lawn Mowers, etc.): Runs like crap, engine model type, air mixture

Question
I was wondering I have a 20hp craftsman tractor and it idles like crap,ive replaced the spark plugs/fuel filter/air filter/the tractor is used year round.I was wondering what the carb adjustment on the top of the carb should be,its a v-twin..

Answer
If you have an idle air mixture needle on the carb it should be set at 1 &1/2 turns out from a GENTLY seated, finger snug, position.

What brand engine is on the tractor?
What is the engine model, type and code/serial number?
What is the mower model number?
Let me know
Eric