I put a IMS 4.6 on my first XR650R in Feb. of 2000. I have since purchased another XR650R and kept the original IMS 4.6 tank. This tank has seen over 7000 miles of hard riding. I even went over a cliff on my first XR650R but the tank survived just fine as did the bike. I have never had a problem with IMS. I have purchased their tanks for all my bikes except the 525 EXC, it has a Clarke tank.