got an Lt80, had it about 5 years. Kids ride the crap out of it. Here a while back it got to starting real hard, after it started it ran fine. Could ride for as long as you wanted, but once you let off the throttle it would very slowly start bogging down til it would die. It wont start then. I discovered tonight though, if you unscrew the throttle cable out of the top of the carb and lift the needle valve out it'll start and run fine then. Same deal, ride as far as you want but once you stop it'll start bogging til it dies. Just had the carb cleaned by a good mechanic but it didn't seem to help. I see a lot of comments about the petcock too, this machine still has the original one from the factory in it. I believe the machine is a 1987 model. Got new oil and new non ethanol gas in it. Thoughts????

 

You have tried adjusting the idle screw . Will it stay running with the choke on. Also have you checked air filter over the last 5 years. A compression check should also be done.

 

What he said.