Post Leisure Dynamics Black Widow

Is it my poor eyesight, or the angle of the picture? It looks like there is only one vent/fill tube nipple on the back plate?  On the 1975 BW there are no vents on backplate, only on the tank.  Thanks,  one eye Marley

Your eyesight is still good. The plastic backplate on these used a single nipple filler with a pin hole vent hole directly next to it. I recall these in use when I purchased Cox Babe Bee engines in and around 1987-88. I would purchase them and sometimes receive a metal backplate and sometimes a plastic version. I'm quite surprised that this didn't cause a lawsuit. You would fill through the nipple and the fuel would come out of the pinhole with enough force to squirt as much as high as 3' which usually ended up directly into your eyes if you didn't know any better. The non vented tank crippled the performance of the Estes so called Black Widow. It suffered inverted and as mentioned, the power didn't match it's earlier variants. The fact that you could no longer fly inverted renders the engine useless in my opinion. I would drill the tank and install my own tubes into it. While I've found the plastic backplates to work well, I wasn't a fan of the plastic tanks due to having them develop air leaks between the tank and backplate. Ken