Mini Manx, Triumph Triton or Norton 3.5 gallon fuel tank for sale. This tank has been used on my 500cc Triumph Triton (Wideline frame) for the last fifteen years. It is unpolished and physically sound, having been rewelded and pressure tested recently. The threads for the taps are pristine as can be seen in the pictures. I was happy with the tank as is, for my track bike, but it would polish up nicely.