Hi Y'all. I'm new here. I have spent the last 3 evenings trying to get this thing running again. My ATV just stopped starting up seemingly randomly. When I hit the electric start it turns over and just tries and tries but never starts.

I have:
Installed a new carborator.
Checked to see that fuel is running down the fuel line when I remove it from the carb.
I am using the electric start function.
It runs and fires if I spray some carb cleaner into the front of the carb.

So I'm pretty sure it has spark because it fires up with the carb cleaner. I know its not the carb because I just replaced it. Fuel just runs and runs out of the fuel line if I remove it from the carb and turn open the petcock.

Could it be bad fuel or something I'm not even thinking of?

 

Check properly for a spark, change plug and do a compression test. Check for water in the float bowl. 250s have a known fault, in that the cam chain tensioner breaks and lets the chain jump a few teeth, putting them out of time. However, if compression is down (below 90psi) it could just be faulty valve clearances, wear in bore or rings, or a light seizure.