The burning time of dried kelp blocks is 4001 ticks.

Steps to reproduce

1. Place 64 dried kelp blocks into the furnace.
2. Put a hopper on top of the furnace and place a chest on the hopper.
3. Fill the chest with a large quantity of combustible items.
4. Position another hopper below the furnace to collect the output.
5. Use the '/tick sprint' command to accelerate the game.
6. Wait for some time.
7. Open the furnace and observe that the time for the fuel to run out and the time for the items to finish burning are not synchronized.

Since my English is not good, I used chatgpt to translate into English, and used Google to translate back to the original text to try to make sure it was as close to what I wanted to express.