i have a 250 4x4 quadrunner with low miles it only got ridden once or twice a week and in storage all winter. i got it out and you have to crank it forever to get it to start and it wont idle unless you keep giving it gas and it wont run at low rpm. took the carb off cleaned it and replaced just about everything in it put it back and still the same thing. would love to get this fix it goes every where you want to go

 

I would go through the carb again, clean and examine everything.