How to stop oil from coming inside spark plug no#3 cylinder?

i will check compression monday. ring or valves i do not know but visible problem is spark plug soaked with oil. in your knowledge of Honda engines what is the possible cause?

I'm guessing cracked head or worn valve guide.How bad is the misfire? Put a vacuum guage on it see if it stays steady or fluctuates.

thank you for the response i found the problem.

well, what was it?

deep well o-ring