Originally Posted by mikec

Well, I think I finally found the problem. Top tension. I decided it had to be a setting. So, I basically tried every combination of bobbin tension, and upper tension. I found that the higher the top tension, the less the underside bunching. My only problem now is that I have the top tension at max (10), and I am getting 97% good stitches. I imaging an 11 or 12 would get me 100%

Only problem is that there is no 11 or 12... So I am thinking that my top tension adjuster is bad, worn out spring perhaps? I'm going to see if I can replace the assembly before I start sewing my $1000 boat canvas. I finally see light at the end of the tunnel!