Help with Pfaff 335-G

[Hickenbottom]

Hello,

I have Pfaff 335-G. All was going well until the thread bobbin thread started breaking and I was getting a birds nest. I tried adjusting tension to no avail and then started messing with the bobbin tension. Tried re-threading multiple times, changing stitch length and still nothing worked. I had previously fixed the timing on my server so I made the decision (probably then wrong one) to go ahead and take a look at the timing with the adjustment manual as a guide. I’ve now adjusted the timing soo many times to what the manual said and even tried it a little bit different but it still won’t work!!   I checked the height of the needle bar against the manual and it was not the same so I adjusted it. This may have made things worse and I was stupid enough not to record the previous needle bar height. I have purchased the timing tools the manual lists and have used them so the timing is as the manual stated but it doesn’t work. It creates loops but sometimes on the second go around the hook seems to catch both the upper thread and the bobbin thread and pulls them around at the same time. When I add power it just gets all tangled and breaks the thread. Occasionally the top bobbin thread will form a few stitches but the top thread forms a bird nest. Also, the bobbin thread seems to fray when I pull on it. I’ve made sure I’ve threaded that correctly too. I think it has something to do with its position it gets in when the upper thread first catches it and pulls it through. It gets pulled through this little hole, gets stuck and then breaks. I’m afraid I have totally screwed up the machine even though I’ve adjusted it to the manual. Even double checked I had the right manual. 
 

Anybody have/had a similar problem? 
 

Any advice? 
 

Thanks!!

[Wizcrafts]

1. First, make sure you hold back the starting threads for a few stitches to lock them in place.
2. Next, try different thread. Thread that breaks coming out of the bobbin is suspect. You may have old defective thread.
3. Third, replace the needle with a new one that best matches the size of thread you are using. Consult this needle and thread chart.
4. Hand wheel the machine and watch the formation of the loop as the hook picks it off. This may give you a clue as to what is going wrong.
5. Loosen the bobbin tension spring and feel for burrs. Also inspect the bobbin case thread slot.
6. Remove the feed dog and throat plate and check them for burrs.
7. Make sure that the check spring bottom stop keeps the top thread taut until the needle fully pierces the material, then stops moving down.
8. Note the position of the check spring screw inside the curved slot. Moving it one way or the other will give a little more or less slack in the thread.
9. Make sure you have enough top thread tension to pull the knots up into the middle of the material.
10. Don't use thread that is too large for your machine.

[imawalkingfoot]

Have you checked this video?

https://www.youtube.com/watch?v=KQihrdtPIxE