The molded area of the fuel tank to which the fuel petcock is mounted is too brittle, due to an incorrect temperature during the molding process.
The brittle area of the tank can crack and lead to a fuel leak and fire if an ignition source is present.
What to do...
Do not operate affected generators until the modification is completed - replacement of the fuel tank with one that has been correctly molded.
Contact your Yamaha Dealer to have the fuel tank replaced free of charge.
Identified generators sold from July 2018 to November 2019
Yamaha EF2000iS Portable Generator
7PB 0329803 ~ 7PB 0330916 - 2018
7PB 5080473 ~ 7PB 5080496 - 2019