My 400 ex will not idle. I tried the turning the idle adjustment but nothing happens. Has anyone had this problem or know how to fix it?

 

Most likely a clogged idle (pilot) jet. Clean the carb....

 

And don't forget to clean and reoil the air filter , and after you clean the carb add Sea Foam to your gas to help keep your fuel system clean ; and the Sea Foam will clean your combustion chamber of carbon depost buildup as well as keeping your fuel fresh longer !

Sea Foam has a drying agent that will help to keep water from forming in the fuel tank , you can get Sea Foam and Deep Creep from most any Auto Parts Stores , Auto Zone , Advance and O'Reillys Auto Patrs Stores ; i get it at my local O'Reillys Auto Parts Store for $5.99 + tax for a 16 oz. can Directions are on the can !

Deep Creep is the same as Sea Foam , only it come's in a spray can it's the best fuel cleaner/stabilzer fuel additive i've ever used ; and in the last 20 yrs. of Small Engine Service and Repair i've tried them all and Sea Foam and Deep Creep is the best all around additive you can get that does it all in one can ! ...............