Tractor Repair: ford 9 n wont start, ford 9n, firing order

Question
I have replaced the distributor and all wiring on my ford 9n and it still will not start.  I have fire at the distributor.  Any Ideas ?

Answer
 Make sure the firing order is correct and that there is spark at the spark plugs.  Possibly it is a fuel problem and not an ignition problem.  If the gas has been in the tank for a long time, it should be drained and fresh gas put in.  Make sure there is nothing plugged and that gas is getting to the carburetor.