we drain out our tank after everyday. (practise and racing)
We found that it gives a tiny little advantage having fresh fuel as there is still more oxygen in the petrol. (i know its small but when you do s1 every little helps
) This is on the TKM 4 stroke engine.
Also everysingle petrol tank is between the rails and the easiest way we found to do it was just to remove the floor try and take it out from below and therefore you leave the steering alone
this is on a tal-ko Raider Ms4 2006