How Does The Reserve in A Fuel Tank of A Bike Work?

Ever Thought, What actually happens when we switch the knob to reserve?

A regular motorcycle Has main tank and a reserve tank. There is no separation between them but they belong as a whole tank. The knob that is present at the left side down under the bike enables us to switch to either MAIN TANK, OFF and the RESERVE TANK.

In reserve, a smaller valve gets opened so it allows the engine to consume less fuel when compared to the main tank.

Knob

Assume, Your bike tank has a fuel capacity of 12 liters. So if you fill the tank completely, some of the fuel goes to the other side of the tank depending upon the reserve capacity of the tank.

Generally, Most Of the bikes have a reserve tank capacity of 1–3.5 liters. Consider a Bike, Which has a 15 liters fuel capacity and a reserve capacity of 3.2 liters. So, if we completely fuel up, all the 15 liters remain in the same tank as a whole, We can consider 3.2 liters Fuel Remain between  Main Tank Level And Reserve Tank Level.this is Reserve Fuel.

So if we go out on a long run and we forget to fuel up and somewhere we find ourselves with no fuel, then this reserve plays its role. We need to just turn the knob towards the reserve mode and then the bike starts again. The small amount of fuel that is present helps us to go to the nearest petrol bunk and refuel.  

There is no rule that only we must drive in the Main mode and not the reserve. Even if we put the knob in the reserve mode and drive, there is no problem. But there is no point of a little fuel left when the fuel is completed. It means the reserve mode consumes both the main and the reserve fuel. If that’s the case, in long runs we will lose ourselves somewhere.

So it’s better to put the knob in the MAIN mode always after refueling. If the bike stops suddenly, then we can turn the knob to reserve and refuel.