John Deere L120 With Briggs 20hp V-twin

ok, i believe i solved the problem. after watching the videos on this carb i noticed that THE JETS ARE MISSING. wow.... i've never seen carbs where the jets were held in by o-rings. i assumed that the jets were fixed further up into the orifice. then i watched the video. so i ordered two main jets even though i think that one jet is bigger than the other. i installed them and i'll put the carb back on the john deere L120 this eve. what i think happened is that the o-rings holding those jets in-place shrunk and the jets fell out. what's really weird is that i couldn't find them anywhere. it's possible that they fell out the last time i "fixed" this carb and the float was sticking creating a lean condition allowing the engine to run well. isn't that a coincidence? i can't wait to fire the pos UP and see how it runs. my lawn is getting long in the tooth...

You are not alone.
The Nikki fitted to a lot of inteks has a similar system and they regularly come in sans main jet, Particularly from clots who think you blow out carbs with the compressor set to 120 PSI

those guys are old-school tinkerers who are used to metal carbs. lol... but i think that this is a flawed design. the jets are all destine to fall out one day. regardless, i'm glad i figured this out. the tractor starts right up now and runs great.