On catheram there is a deviice in the tank. There is a vertical bit and an horizontal bit
There are two things than can be adjusted
The level of intersection of both bits, so that this is roughly the half tank level
And the lenght of the horizontal bit so that its travel around the axe is as big as possible to have a fine measure
Both are known to be poorly tuned in Caterham, but I dismantled the system on my CSR and adjusted with a lot of car, putting in and out gas with an external pump by five liters iterations
