broken spark plug

If the ez out is not broken off you should be able to remove it by turnig it backwards. To keep from breaking off the ez out in the spark plug threads use the largest size ez out that will fit. Another option, as you suggested, is to drill out the remainder of the old spark plug. If you ruin the threads in the cylinder head you can repair them using a helicoil insert. You should be able to find a spark plug thread repair kit at most auto parts stores. It should contain everything you need to repair one spark plug hole. If you go with the helicoil repair you need to drill out the old spark plug hole anyway so that may be a better choice from the start.

The above can work but something else you might consider it this, that the plug is likley seized and/0r cross hreaded in there anyway so attempting to remove it without drilling is wasted effort. My suggest is to try to drill it out but drill about 20 to 30 thousandths small than thread bore and then when through plug you should beable to colapse it and remove it with minimal or no material lost in head plug hole and then you can examine what is left and choice best repair course. If you do this successfully and theards are not damaged, you may be able to just run a tap through it to clean it up and be back is bussiness. When you drill it you want a nice carbide or nitrate bit and a good 1/2 ich drive drill that can maintain a good low and steady cutting speed (about 300 to 500 RPM) and keep bit oiled will drilling. Do not use a smaller high speed drill motor as a good steady low speed that does not bog is important for a good controled and fast cut.

----------------- The SnoMan

if you put some air in the tailpipe and turn the crank by hand just till the air blows out the plug hole most of the chips will blow out as you drill.. i use duck tape to seal up air line in tail pipe..lucas

Nice tip!!! :)

----------------- The SnoMan

Wow, sounds like you do that a lot.

anyway...

I assume letting WD-40 soak into the threads for a couple hours did not free it up right.

Dan