Sounds like you are making some progress. I know the book says 70-100 on the twine disc, but experience shows that 100 is too tight. The knotters will pull some twine back out of the disc during knotting. If it is too tight the knotters cannot do this, and the twine will shatter so no knot. Before you readjust these, check the condition of the flat springs that provide the tension on the twine disc. It only takes one spring, but it has been very common to use two springs. If they are rusted together they will not flex, and this makes the twine disc way way too tight. To check those springs you have a 3/8's bolt and lock nut that holds them in place. Remove it completely if you have two springs and make sure they are not rusted together, and then put a little never sieze between them.
How much clearance is between the needle and the twine disc when it passes the disc? Check right where the twine comes off the guide on the needle. Very small clearance here, 1/64 or so. Basically just not touching.
For the tucker fiingers, bring the needles up until the tucker fingers start to come across the needle. The tuckers should just barely clear WITH OUT touching. If these are not close to right, it will not bring the second twine across the bill hook.
Tension on the bill hook is not too critical. 7 is fine. Basically tighten the adjusting nut down so you can get the cotter pin in, and this is usually correct as long as the spring is not broken.
How are the springs on the hay dogs? Replace them if needed, and get the U shaped wire that goes with them. Usually the U wire brakes and the spring falls out. Especially check the one or ones on the bottom.
With no hay in the baler, at the beginning of the chamber its self, there is a plate on each side of the chamber that has what looks like a bunch of half moons pressed in it. It is called the hay resistor. If these are worn out, ie the moons are gone, you will not tie well at all. The hay resistors and the hay dogs hold the hay back during tying. If they do not work, the twine position gets all messed up.
One more thing to check and make sure okay, and that is the brake on the needle lift are. Not use, but I think it is on the lift are itself. Make sure it holds, but allows proper movement. I cannot get the parts book on like, or I would check this out.
In the OM, there is a great section on diagnosing knotter problems. It has bunches of pictures of the various problems. This may be a help when you get closer to working.
Lastly what kind of twine are you using, plastic or sisal? If the bill hooks are not for plastic, you need to use the sisal. If you have the plastic hooks, plastic does a much better job. If you can get the 210 pound plastic, you can use that as it is the same size as sisal, but it is uncommon to find any where.
Once you get things about right, you should be able to go thousands of bales with out missing one. My personal best streek has been over 5K on my 336's. Fell free to send any other questions, and please let me know how you make out.