I bought a new Pulsar 150 motorcycle.

While reading its specs in the user manual, I found:

Total litres (reserve, usable) = 15 litres (3.2 litres reserve, 2 litres usable)

I assume that 15 liters is the peak amount of fuel in tank.

  1. What does this mean?
  2. Can anyone explain what is 3.2 L reserve and 2 L usable?

The tube that draws fuel out of the tank is not at the absolute lowest point of the tank.

This means that when the fuel runs almost dry, the last few drops won't be picked up. That could be because of airlocking or there is a contour in the tank that leaves a small amount of fuel inaccessible.

In your case, there is 1.2l of unaccessible fuel. This phenomenon seems to be a lot more common on bikes than four-wheeled vehicles. I believe this is because of the way the fuel tanks are mounted in the two chassis types.

  • what is 3.2 liters reserve.. ?, If petcock is in ON position and the fuel in tank is 3.2 L then bike will not be able to consume petrol ( and we need to turn the petcock to RESERVE, in order to use the 3.2 L fuel), Am i correct ? – Saif Mar 20 '15 at 14:31
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    With the tap turned to reserve, you will be able to use 2l of the 3.2l in the reserve. The other 1.2l is unavailable. – Chenmunka Mar 20 '15 at 14:38
  • The bike has two tubes going up through the bottom into the fuel tank which suck up the fuel. One of those tubes is longer than the other (so ends higher up in the tank). When you put your petcock in 'ON' position, you select the longer tube. This means that if you run out of fuel in the 'ON' position, you can move the petcock to the 'RESERVE' position - switching to the shorter tube - and still have enough fuel to go fill up. Some people just leave their petcock in 'RESERVE' all the time: this is bad practice, as if you run out of fuel, you have no fail-safe mechanism. – Mr. Meeseeks Oct 31 '16 at 9:12

Tank full capacity is 15Ltr. It will consume 11.80 Ltr when petlock is on and whenever 11.80 ltr is used,you have to turn the petlock to reserve unless your bike stopped. And when you turn the petlock to reserve it will use only 2 ltr of petrol. The rest 1.2 ltr of petrol can be used when you drive bike long in reserve but it creates problems for you.First is that your bike will go stop after running about 200 mtr due to airlocking because of insufficient petrol.


Tank stores 3.2 litre of fuel for reserve ..but you can use only 2 lt of petrol because its usable capacity is 2 lt only..rest 1.2 lt of petrol are used when the bike runs in reserve for long time


It means that you have 2 liters with the petcock switched to 'reserve'.

IF you run out of gas when the petcock is in the 'On' position you can switch to 'reserve' and get an additional 2.0 liters to get to your next fuel stop.

So you get 2.0 liters of driving time. The 1.2 liters left in reserve is unusable because it can't get into the petcock. Your total reserve is 3.2 liters with 1.2 liters essentially wasted.

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