Hi wayne. The clutch is a copy of one made by 3rd Millenium Energy, who no longer offers them. They used to make them for the later Whizzers. Whizzer started making their own leaving the company with some left over. I purchased several on ebay for my bikes because I found the spacing of the pulleys was perfect for my Briggs bikes. My friend, John, builds Harleys, and does other machine work in a small Huntington Beach shop. I got him into building motorized bicycles about 20 years ago. I used to ride my red bike to a radiator shop in the same complex for a Christmas party. John would always come over and look at my bike until he made his own. A few months ago he rode my race bike with one of the auto clutches and had to have one. With them not being available anymore, he decided to make his own. We discovered they were just heavily modified Max Torque units. After purchasing the 5 or so bearings he still had to do a lot of machine work to duplicate it. He's going to make one more for me but I don't know if he will offer any for sale. He did say that he could not sell them as cheap as the mass produced ones. If he decides to, I will post it on the forum. I have several friends who would also like to buy one. They freewheel nicely at idle and hook up real strong allowing for fast take-offs. The first one I bought is still working well and I also have one on my 8hp Briggs bike with the same results.