How can I remove a spark plug with a rounded head?

Question

Its a 1999 Suzuki Bandit 1200s.

Answer 1

So you're saying you've rounded the corners off the flats of the spark plug? On a bike there's usually limited space to do anything. Tried both open end and box wrenches? Needle nose vise grips? Just pretty much have to get that quarter turn to break it loose and it should come out. A last suggestion would be to break off the ceramic insulator and try to get a large easy-out where the insulator was. Good luck

Answer 2

How the hell did that happen? Must be way too tight...
Using a good six point socket, the plug should never have rounded.... It's a spark plug not a lug nut.
If it's totally rounded, you MAY be able to get it out by using a hammer to pound the next size smaller six point socket onto the plug. Use a GOOD solid six point socket. Not a "made in taiwan" 12 point socket.
Spray some penetrating oil around the plug threads.

Answer 3

Always give year, make, engine size and model # when asking questions. We need all of that info to give an informed answer.
Knowing what bike you had, would tell us if the spark plug is recessed in the head.
And be a little more explicate with your questions.
At first I thought you meant a round cylinder head.
If the spark plug is recessed, needle nose vice grips (locking pliers).
I could give you more options if I knew what bike you had.

Answer 4

Try the next size smaller in a metric socket or a 12 point.
If it's not too small , use reasonable force to tap it on with a hammer once it's on there tight put your driver on and do your thing.

Oh! wait, is Your head rounded? or the spark plugs?

Answer 5

You can't remove a spark plug using your rounded head. You need to use a spark plug wrench.

Answer 6

Go to your local hardware store or [Halfords] and ask for a mole grip, it's a kind of vice grip spanner

Answer 7

Use a socket instead.