A while back I found this website. eagle-research.com I am not affiliated in any way here, I was simply looking for a way to get better fuel economy, turns out I found the cheapest way to 8km/l for a 22r, an improvement from 5.5km/l Total cost R5.00.
Basically the idea is that you pressurize your float bowl so that the carburetor is balanced, it essentially enhances the emulsification of the fuel among other things without you changing anything. Installation is simple with all the requirements being some fuel hose, a vacuum source and a tap to decrease or increase vacuum, you attach on side of the hose to a vacuum source (in my case I installed it on one of the many vacuum ports I had available on the carb itself and attached the other to the vent tube on top of the float bowl with the tap in between. Too much vacuum kills the engine, to little wont work, once you've turned the tap till a little way before it dies you have it tuned. That's it.
![Image](https://image.ibb.co/hBi2NH/4d61494704221ee2b7493751b22f5ec5.jpg)
If you guys have any questions or would like to even have a look at the book this guy sells on his website I would be willing to share.Good info like this is priceless.