I recently purchased an Omega industrial sewing machine. Upgraded from the 1/3 hp clutch motor to a servo from Techsew. Being inexperienced the clutch motor was scary fast and I liked my fingers the way they were. It only came with one needle, 140/22 is all I could read on it. I will be sewing anything from 2-3 oz. leather to as thick as I can....I've run 8-9 oz. through with no problem. I am using #69 thread through the 140/22 and find it "balling" up underneath and extra thread coming up from the bobbin but not all the time. I guess my question is after much looking through the forums, am I using the proper thread for this needle or am I even using the right needle? I saw in one of the charts that the 135 x 17 is the same size needle; is this correct? I have played with the tensions somewhat but if the needle /thread size may be the issue, I don't want to beat my head against the wall. Any advice would be helpful re needle size vs: thread. The needle #'s are confusing to understand. Thanks in advance!