I think this tank came off of a 1986 or 1987 Honda XR250 / XR250R. 



It is in great condition, with some white discoloration from sun rot. Someone started to clean it up, and it does look great, but would need more work, or use it as is. The petcock screws are loose and will need to be tightened. The petcock may needa new mounting seal & may need to be rebuilt. 

No cracks, no repairs.