When I got my Cowboy 4500 leather stitcher I noticed that I could not wind bobbins without babysitting the machine and wiggling the engagement lever. The problem was two fold, one was a very rough piece of metal in the engagement mechanism and the second problem was the drive disc wasn't pressing hard enough on the rubber drive wheel.
I am going to post a detailed how I fixed it post to our website, I hope to have that up sometime next week.
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