Tractor Repair: 1962 Ford 2000 tractor - engine wont turn over, starter solenoid, battery cables

Question
QUESTION: Recently rebuilt engine. Been running fine. Started up, drove about 1/2 mile, shut off for few minutes. Will not start back up - won't turn over, just nothing when hit the switch. Has gas, battery cables look good.... Any ideas what could be the culprit?

ANSWER: is the starter trying to turn the engine or is it not engaging  if it is not engaging check the battery terminals check your earth and your positive going onto the starter
if it is engaging but not turning the engine see if you can turn the engine by the pulley in front and get back on to me

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QUESTION: Thank you. No, starter is not engaging at all. Thinking it may be the starter safety switch since occassionally it will spark. Thoughts?

Answer
with the gear box in neutral use a wire to take power from the positive to the small wire going on to the starter solenoid if it starts now you are probably wright about the neutral switch if it doesn't turn you either have an earth problem or your starter is bad seeing as the engine has been re-conditioned there is a good chance an earth wire is loose or battery lug also worth checking has the block been painted as this would interfere with the starters earth if it gets its earth from the chassis