Sometimes they ask me. I answer Given: Rotax 650.1c cylinder block, aka BMW F-series. Since the sample of the gasket was lost, and the other modification does not fit from the word "at all", it was necessary to make an impression. Of course, if you have a special tool, it's easy. The block already had guide pins. We use 0.5 mm thick electrical cardboard for printing. A hole of the required diameter was punched in a deliberately larger piece of cardboard, installed on one of the guides and with a wooden handle (the handle from a file is quite suitable!) An impression was made from the second guide. The cardboard lay flat, and now you don't have to worry about lateral shifts. Next, using the same pen, a ball-bearing finger, and a small hammer, all the holes, channels, and outline were carefully printed. I categorically do not advise smearing the surface with oil, graphite grease and other nonsense - you will get something extremely blurred and not clear at all!! I prefer to make a print with a wooden pen. Even without help, the hammer comes out very clearly. It is better to take cardboard about 0.5 mm thick, in no case corrugated, you can also use Whatman if there is no denser cardboard. Our print is ready and you can start making the lining. The location of the channels is taken from the photo of the original, according to our experience, the dimensions will be maintained.