I'm working on a trail master gokart it will start then shut rite back off. Push gas in it will start but won't reve it act like it missing clean carb same thing got new carb same thing

how old is the gas? Sounds like a bad tank of gas.

it is a garantee that the main jet is stoped up with that grayish dried gas minerals..this not in the main jet valve you can remove,but actually in the bore on the carb body... you can try to use torch tip cleaner to open the hole ...hope you the best ....it is a very hard substance...someone tried starting the bike after being set up for a while without removing carb and cleaning first.....sincerely;R.B.V.

clean/replace air filter

Yes it could be

u may not hav cleaned it rite or the jets need ajustn--seek a repair manual on that model ride

first check for spark if no spark check the oil some have a low oil shut off next try and spray some carb cleaner if it fires on that you may need to clean the carb

There could well be a build up of sediment and debris in the main jet to the carburetor. It is easy to get to and clean. It is the brass bolt that holds the lower float bowl onto the main body of the carburetor. To clean it, drain your gas. Remove the bolt and external washer UNDER the carburetor bowl. Clean out the bowl of any sediment and/or water. To clean the brass bolt, use no metal objects. Carb/Choke aerosol spray cleaner will do the job. Pay close attention to the hole in the bottom of the bolt and the very small holes about 2/3 of the way up the bolt. Clean till shiny with holes cleared and reinstall. Your fuel flow problem and shut off condition may be solved.

ok you have what sounds to me a blockage in the carb. take it off and thouroughlly clean it. check the diaframs in the carb to see if they are hard and stiff. if they are hard and stiff replace them and clean the carb really well and see if this works.

Ckeck and clean the Carb, Change Fuel Filter if it has one.