Kawasaki and Maruyama both recalled backpack blowers due to fire hazards.
Kawasaki recall information, including model details, is here on the Consumer Product Safety Commission website.
The Maruyama recall details are on this page of the same site.
Both of these have gas tanks that can split and spill. If you have blowers of either of these manufacturers, confirm the model, and, if it is recalled, tag it out of service immediately.