i don't think you could push the clutch pedal all the way in, if it was in backwards
i had this problem when i went to the 4k from the 3k
the flywheels were different and it wouldn't turn over, then the starter got stuck, then it wouldn't shut off, then it burned out, then i got a n.o.s. one off ebay, went through the same thing, then put a gear reduction 4k one on it, no problem.
i would put it in 4th, then push it forward to see if it's jammed