Those are the mufflers, and I would consider that normal. It is only slight surface rust from sitting outside.
The mufflers and the pipes leading to and from them are usually made of steel that has been somewhat "rust proofed" by galvanizing or some other coating. This coating is applied before they are welded together. The intense heat from welding (far higher than a running engine) destroys the coating at the point of the weld. That is why you see rust on the welded spots, but not on the crimped seems of the two halves of the muffler. That muffler will still last a very long time. If you are storing your machine inside, then it will likely last for the life of the machine.
The mufflers and the pipes leading to and from them are usually made of steel that has been somewhat "rust proofed" by galvanizing or some other coating. This coating is applied before they are welded together. The intense heat from welding (far higher than a running engine) destroys the coating at the point of the weld. That is why you see rust on the welded spots, but not on the crimped seems of the two halves of the muffler. That muffler will still last a very long time. If you are storing your machine inside, then it will likely last for the life of the machine.