300cc atv There is no gas flowing from the tank to the carb. There is plenty of gas in tank but can't get it to carb.

Put a new battery in it and add it to the price. ATV batteries are abused, they need a trickle charge if not used for a month. Expected life in a neglected state would be 3 to 4 years. Is it the original battery and 8 years old? Strip and clean the carburetor.

https://www.batteriesplus.com/battery/atv/yamaha/grizzly-300-automatic/300cc/2012

https://www.google.com/search?q=2012+yamaha+grizzly+300+clean+carburetor

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sounds like fuel flow from the tank is having trouble and its running off the gas built up in the bowl. could be the petcock, tank strainer, tank vent clogged

Try running it with the cap off the tank. Sometimes the cap will fail and wont allow air back into the tank when you draw fuel from it. This starves the engine of fuel.

Hey Larry,

First, does the carb have gas in the float bowl? There is a screw or bolt in the very bottom of the carb's float bowl, loosen it and gas should flow freely, IF NOT,, there is the first problem you need to address. Check this and let me know. Doe the motor turn over freely? Does it have GOOD compression?

Check your gas cap - some are vented to allow excess fumes from building up. It gets clogged or the mechanism takes a dive - it's basically just creating a vacuum. Try it without the cap on. And sometimes - if you're float is stuck - you can tap on the bowl and the float will unstick.

#1 sounds like a fuel delivery system issue. Make sure the fuel tank flows freely to the carb. (remove the fuel line from the carb--from the gas tank and turn on the petcock--gas should flow freely) The needle and seat may need to be cleaned or replaced, this controls the flow of gas into the float bowl of the carb.(remove the drain screw from the bottom of the carb (with everything properly assembled- petcock on)..gas should continually flow through the bottom of the carb --10-15 seconds of continual gas flow will make sure its flowing properly! Both of these sound like a solution to your problem.

is it running out of gas? backfire is caused by a lean condition. I'd check the fuel path from the tank to the carb and clean the carbs. could have something floating around in there occasionally blocking fuel flow.

please 1. check fuses 2.check spark using a timing light then 3. fuel with a fuel pressure gauge if no spark replace ignition module; if no gas replace fuel pump

Dirt may have clogged the main pilot jet try taking the carb appart and blow carb cleaner thew both jets while your at it

The spark plug is on the left side (shifter) of the head,,..?/ this is August.. if the atv has been sitting the carb may need a qualified professional to clean it again.. Replace the spark plug before you squirt anything in the engine...