It is important for you to tell us if your tractor has a 6 volt or 12 volt electrical system. The troubleshooting is different based upon the configuration of your engine.
There are three tools you always need to have in your N tool box: a 3 inch piece of wire w/ alligator clips on each end, an old spark plug w/ the gap opened to 3/16” and a 7/16 box end wrench. And, you really do need a working ammeter. With these tools, you can quickly narrow down most N problems to spark or fuel.
Next time it stops, check quickly for fuel then spark. When I say quickly, I mean get off the seat, grab the tools & do it right then. Do not wait a minute or two. First, check for fuel. Remove the bolt in the bottom of the carb; as long as the fuel is turned on, you should see gas flowing out of the carb. If it’s a dribble, or runs for 5 seconds & stops, or none at all, you have solved half the problem: it’s fuel related. If gas flows well out of the carb & only stops when you turn it off at the sediment bowl, chances are very good it’s not a fuel problem. So, next, crank the engine & look at the ammeter. What is the ammeter doing? Does it show a constant discharge, no movement at all, or does it dip? Next, get the old plug, ground it to a rust & paint free spot on the engine, turn the key on & crank the engine. If the spark jumps the 3/16” gap, you probably don’t have a spark problem. If it won’t jump the 3/16” gap, you have a spark problem. If the ammeter shows a constant discharge, or doesn’t move at all, that also tells you that you have a spark problem. Jump the ignition switch w/ your jumper wire & see what happens. If it runs, you found the problem.
If it does not have gas coming out of the carb at a steady stream w/ the bolt out, you have a fuel problem. First, remove the gas cap. Your vent could be clogged & it vacuum locked. If that doesn’t work, tap the carb bowl w/ a hammer handle in case the float is sticking closed. (don’t whack it w/ the head of the hammer; you can crack the bowl). If you still don’t see gas flowing, the N has three fuel screens; one in the brass elbow, one in the top of the sediment bowl & one on the stem of the sediment bowl in the gas tank. Check the screen in the elbow & the screen in the top of the sediment bowl. (don’t worry about the one in the tank) Both probably need to be cleaned. If you have the fuel knob turned on all the way, it may be trying to feed off of the reserve inlet which is probably clogged. Only open it 2 full turns. Put at least 2 gallons in the tank.
Lastly, all of that cranking & too much use of the choke has fouled the plugs. A weak spark & fouled plugs is not a good situation. Remove the plugs & replace them, or heat up the electrodes w/ a propane torch & reuse them.
50 Tips
