RE: Engine problem
Are you sure you have hot spark? Not low level weak spark. Could be the notorious ignition box. If you have healthy spark and you put gas down the carb. It should crank. Might check to make sure the timing chain did not break or jump timing. Take valve cover off and set to TDC. Take off dist. cap and see where the rotor button is pointing. Should be at #1. If all these check out then spark plugs and wires should do the trick. Let me know if this helps.