1984 50hp 2 stroke 4cyl help

Can anyone tell which 2 look normal?

how many hours are on these plugs?
what number are these?
regardless of hours they are showing heavy soot and several factors come in to play here.
IE, timing issues, cheap oil, too much oil, incomplete combustion, old stale gas etc.

To answer your question I’m not seeing anything different between the 4. All look to have the same issue.

And I’ll agree with everything Iowaboy said.

They look wet so I’d look into an oil issue first. Get new gas and a good oil and mix appropriately. Also install new plugs.

4 cylinder 50hp? Got to be some good torque on the engine!