I just put a new fuel valve on my 2000 polaris trailblazer, just to have it leak as bad as the old one, it leaks between the tank & valve, could I get away with using a sealer? Like permatex?, It came with a gasket, should I use another one with it? I don't know what else to do......also is 8mm the right size for it?

 

They make this that can help,but a new gasket should have helped unless there happens to be a crack in the tank where the nut inserts are. I'd look over this area carefully before using a sealant.https://www.permatex.com/products/ga...lange-sealant/