Ok first if you have to crawl under it to work on the carb.. Don't touch it!! lol. You most likely have a 2 bbl non computer controlled carb on a r22 engine. Am I right? First I'd check the fuel Fuel Shut-off Solenoid. Check to see if it clicks when the key is turned to the run position. You can grab it and feel it chick or hear it click. If it does not click, check for 12v/power with a test light or meter. Vacuum leaks can cause no idle That saying that all else is working fine. There is many of other things that can cause this. But this is just a place to start. Carbs are not an easy thing to work on. It's best to let some one that knows what they are going look at it. If you were in Northeast Pa I could tell you right where to take it.