Mazda B2000 motor siezing after it turns over twice

You could either have the timing at 180 degrees out or have a bent crank or cam shaft. Pull the dipstick and check for metal shavings. If it's clean, then pull the timing belt and #1 spark plug. Turn the engine by the crank shaft bolt, NOT the cam shaft bolt. Have a screw driver or something in the spark plug hole and slowly turn the engine till the piston hits it. It shouldn't cause any damage, and be close to a timing mark. Then line up the timing mark on the Crank shaft and the cam shaft for T.D.C and reinstall the timing belt and spark plug. If it still hangs, then you may need to pull the head and check for a bent valve.