Hi, a good tip when changing spark plug is to just loosen plug, remove socket and push on some tubing to end of plug then use this to unscrew plug, same for putting plug back. There is such little room to work around the spark plug it would be easy to stress or crack the plug when removing or fitting. I check my plug often and always put some copper paste on the tread to make sure it doesn't seize in there. I did crack a plug prior to learning this tip, also saves burnt fingers when engine is hot.