My rover was running good 2 days ago and now it will not start. I have already bought a new spark plug and that did not help. When cranking it just cranks and whenever I try to press the gas pedal or apply the choke to see if it helps it just makes a loud scratching noise. I am not quit sure where this is coming from but my dad says its coming from the carburetor which I really don't think is the problem. Please help :)