Dumb question- Spark plug socket

What size spark plug socket do i need for my 84 VF1000?

 

i think plugs (and subsequently, plug sockets) come in 2 standard sizes, the smaller of which will be the one you should be looking for. (i think)

 

The spark plug tool in the toolkit provided with the bike works great for the application because you will need a thin-walled socket to get in there.
You should be able to buy one still from Honda.

 

for my 85 vf500 it takes an 18mm socket
idk if it would be the same for your bike, but with mine the socket needs to have a smaller outer radius so it will fit down to reach the spark plugs