I made a big mistake, I was changing the spark plugs while the engine was still hot. I had a hard time removing the plugs. I am currently unable to thread my spark plugs in to the cylinder head. I believe I might have stripped the threads. Does anyone now how much it will cost to fix?

 

The last time I did this, about 1973, I repaired it myself using a helicoil:

http://www.emhart.com/products/helicoil.asp

or you could use a Time-Sert:

http://www.timesert.com/html/sparkplug.html.

You do not need to remove the head to use these. The instructions for the Time-Sert are linked from that page.

 

Thanks much.