I have this issue with my Toro #20073 Recycler 3 & 1 mower and I called the company (Certified Parts Corp) that took over for Tecumseh when they went out of business. They referred me to an EMail address that you can contact to get a free replacement gas tank. You have to take pictures of the engine ID decal and EMail to:
tankshiper@gmail.com. The valid Date of Mfg (DOM) range is 07001Gxxxxxxx to 07120Gxxxxxx. I have not reciev4ed the new one yet but have received confirmation of receipt.
Excerpt from acknowledgment:
Thank you for your request. Please submit the required information as specified in Service Bulletin # 506. After we recieve the required information, a new tank will be mailed to you via first class mail.
Thank You.
CBD Services LLC