I was wondering what size socket I need to change the spark plugs, and if it needs to be thin walled or not. (1990 cbr)

thanks

 

I spent a lot of time agonizing over whether I needed a special tool to do the plugs on my 89 because I did not want to have a plug get stuck, etc.... not be able to retrieve a loose one.
I ended up using the 18MM socket (this is from memory, but I am pretty sure of the size) that came with my Sears Craftsman set, along with the two or three inch straight extension supplied with the kit. It did not have the little rubber liner inside like some plug sockets do, but I was able to reach every plug with no problem. The only hassle I had was the one to the far left (driver's left, fuel filter side) where it was tough to get the ratchet to click in such a tight space. To remove the loosened plugs - for a a couple of them I used one of those long claw type tools that is designed for fishing things out of a tight space, the others I was able to pull out with just my fingers. Sorry I can't tell you if it was thin-walled or not - it was just the same thickness as the others in my set... so it is probably a "normal" thickness.

 

18mm

 

Yep, it's 18mm and a regular craftsman socket will work. Some socket brands won't though. (I know for a fact that the 18mm "master mechanic" brand 3/8 drive won't fit)
I have an actual 18mm craftsman plug socket and it does make the job much easier.

 

careful with the regular sockets though. I was changing my plugs today and the socket fell off the extension. sat just low enough so i couldnt grab it. i had to rig up a magnet to pull it out.

 

I had a frustrating Sunday night because of no plug socket. I have 2 whole bikes and a parts bike that all take an 18mm socket -- I have the tool kits for 2 of them, each complete except for the spark plug wrench. I searched my garage and found spark plug sockets in 13/16, 3/4, 5/8, 21mm, and 19mm. I found an inexplicably large number of short 18mm sockets, and regular deep sockets in everything but 18mm. I was about ready to snap by the time I gave up searching.

Today after work I stopped at Peavey Mart and they had an 18mm thin wall deep socket for $3.99. Inserted the rubber from the 5/8 spark plug socket I never use, and now I'm ready to try again

 

I have the same problem with all the common size stuff.... 10mm, 12mm, etc. I even buy extra in all the sizes I always use and it still doesn't seem to make a difference. Never there when i need the chit.
I'm such a slob. Tools scattered all over my property....