The Wimshurst machine is not "generated by friction", its generated by "induction". Induction is a bit more clever than friction, and you can get a better understanding of it by looking into an earlier device called Belli's Doubler as its much simpler.
I have this exact same model and found it terribly inefficient. Firstly, your neutralizing arms are too horizontal. You should bring them as vertical as possible. The second thing I found was the Leyden jars were just super cheap. Within a short time, one of them developed a tiny hole and short circuited. After replacing both with glass ones I created of my own I was able to draw white hot sparks up to 5 inches in length, or over 1/3 the diameter of the discs. You can stand to improve a lot more of this like smoothing out all the pointed screws and junctions, swapping the belts, changing the ball terminals etc. this should produce an even greater output.
