I have a Ford 8N tractor that will not start, no fuel to the plugs, good spark. It has a 12 volt system. It was running well when it just quit. I checked the intake manifold it's clear and does not seem to have any leaks. Overhauled carburetor still no fuel to the plugs. I have seen a lot of other people with the same problem on the Internet, I have not heard of any fixes. Thank you.