Hello Bill,
I take it that you actually unscrewed the needle bar and let it drop down ? in which case you will have to retime the machine not just set the needle bar height,
First of all put a new needle in the machine, leave the bobbin case out but tilt the machine so you can see the hook closely, with the balance wheel turn it towards you so the needle bar goes down and then on the way up, make sure you have the machine on straight stitch, as the needle bar is on the way up look at the hook, the point should be near the top and just a fraction to the left, stop there and see where the eye of the needle is, it should be just before the point of the hook, if it is not then raise or lower the needle bar so it is and tighten it up,do one revolution with the balance wheel and look at the hook, as it turns towards the needle you can see if it going behind the eye of the needle, you may have to adjust it several times until you get it right, if you thgink you have it right then thread the machine up and test sew on straight stitch and wide zig zag, timing that machine is not very easy for the novice because there are no timing marks on the needle bar, having said that have a look up the needle bar and let me know if there is a score mark in the bar, if not then follow above.
Ken
drivewithken@blueyonder.co.uk, July 2007