JOHN DEERE 14se walk behind mower?

this mower was givin to me and the guy who gave it me was older and had it serviced when i start the mower it took a while to warm up but it worked well the other day i started it and it was doing its normal thing so i took my hand and reved it up with the spring well it died i finally found the spring was off so i put it back on and it wouldnt start the only way this thing will run now is with the air filter off and by me priming it with carb cleaner DOES ANYONE KNOW WHAT THIS PROBLEM IS AND HOW I FIX IT MY YARD IS HALF MOWED and looks like crap