Hey I've been having a lot of trouble trying to remove my spark plug, I know where it is and I can get my spark plug wrench in ther but it seems like the wrench is not deep enough, I bought the atv used and this is the wrench that was in the tool kit but no matter how long I turn for it will not come out, I checked the end of the wrench to see if there was and damage from it slipping but I didn't see anything

 

I think it might be a 16mm Spark plug socket. There might be some build up of dirt, or debris around the base of the spark plug between the base of the plug, and the wall of the head. Try to use a small round mirror & A Light to see down in there, and use a long pick to clean out around the plug. And try to remove the plug again.

Good Luck Bro.........

 

I ended up getting it out, there was a small build up inside my wrench so I had to clean it and push it really hard to get it on the spark plug