Figured it out. Even though the hook timing was ok the hook is touching/pushing the needle as it passes. There should be a gap of 0.05 to 0.1mm and there is none. It actually bends the needle to the left as it passes. Next problem is that I can't get the screws out to adjust anything and I don't want to destroy the screw head. I presume they are not left hand thread or anything? Can I use an impact driver on them???????