18mm
My 2005 Kymco 250cc Grandvista / Grand Dink takes this plug and I use a standard 3/8" drive 18mm Deep socket when changing the plug because none of my other sparkplug deep sockets fit.18MM
Spark plugs use SAE and not Metric. The one that fits it is the one that fits it.
5/8"
Get a spark plug socket and wrench that fits the plug body and remove it by turning counter-clockwise.
18 mm
11/16" (18mm) deep well socket
The CR9EH-9 spark plug needs a 16mm or 5/8" socket.
The BPR6ES spark plug typically requires a 5/8-inch (16mm) socket for installation and removal. This size is standard for many automotive spark plugs. Ensure you have a spark plug socket with a rubber insert or magnet to help secure the plug during installation.
18 mm spark plug socket
most 50cc 4 stroke takes 5/8
You will need either a spark plug wrench or socket that fits the plug. The socket will need to be not only the right size, it will need to be deep enough to allow the socket to engage the nut built into the plug. Be careful not to force the plug if it is seized as breaking it off leads to major projects. Most plugs unscrew easily.
5/8 inch spark plug socket.5/8 inch spark plug socket.