Sb, As TR said as you are working with the early BMW's you are basicly starting from scratch. You'll need to create a electrical circuit whether you are going to install a "Low fuel" light or a gauge. I would weigh the cost benefit ratio with care. You will need to make a way of installing the send device and if that requires welding (there's nothing we like to weld on more than used fuel tanks; serious fun) and most often it'll include repainting the tank. This is unless you are lucky and everything you are installing mates up with everywhere you are installing it into.Hello I have a 1977 bmw r75 and I am building a cafe racer I had the idea to make a fuel level sensor to it. I see that some of the older moto guzzi bike had them. The r 75 has 2 holes for 2 pet cocks would it be possible to use one of the holes for a fule sensor. And do those sensors power a on/off light or a gauge. I have not seen any one do this. I thought that it would be a unique part of the bike. Thanks
Making a sight glass style gauge as TR has said would be kinda cool and not often done but totally old school and at least the bits wont be expensive.