I recently bought an IMS tank for my 98 yz400 from a fellow TTer. My problem is that my stock petcock won't seal up. It uses a very small o-ring to seal to the mating surface of the stock tank, but it seams as though I need an actual rubber gasket for it to seal up to the IMS tank, as the mating surfaces differ. Has anyone had this problem, or heard of it? Also, the petcock is on the rider's left side instead of the right, and I have to turn the stock petcock to the inside to keep the fuel line outlet facing rearward. Has anyone experienced this, or had problems with the fuel line being to close to the exhaust as a result? Thanx in advance.