IMS gas tank?

[Yamaha72]

I have an IMS 5-gallon tank on my raptor, but when I have to take the gas cap of it is hard as hell even if I dont do it up tight. Does anyone else have this problem? If you have an IMS.

[svtbolt04]

it is the pressure in the tank. Make sure your vent tube is clean, if not it creates a suction inside the tank causing the cap to seem as if its stuck in the threads.