stripped plug thread kit--reviews?

[luv2b0at]

Anyone ever try this kit to repair stripped spark plug threads. I am asking for a friend?

http://shop.oreillyauto.com/ProductDetail.aspx?MfrCode=PBI&MfrPartNumber=648421&CategoryCode=3482

I have seen all the past threads on plug thread repair and helicoil vs time-serts vs head removal/weld and retap. The above part looks a bit like time-sert. I justwant to kinow if any have tried the above kit and how did it work?

Also, check out this tool:

http://shop.oreillyauto.com/ProductDetail.aspx?MfrCode=PBI&MfrPartNumber=640811&CategoryCode=3482

You insert the collapsed tap into the hole, draw back on the mandrel to expand the cutting threads, and draw it out as you cut new threads to help prevent shavings from going into the cylinder. This is a new one to me. Has anyone tried it and is it worth the $$?

 

[Howard Sterndrive]

Re: stripped plug thread kit--reviews?

both of those links just go to a sort of base page where it asks for zip code..

I'm interested in that tap. that sounds interesting.

 

[luv2b0at]

Re: stripped plug thread kit--reviews?

I cut the image from the page. It's a "Back[Tap" by Powerbuilt tools.

 

[reelfishin]

Re: stripped plug thread kit--reviews?

The way I read it, Back-Tap is not a Helicoil type or insert repair, it only chases the existing threads. Therefore it's only for minor cross threaded plug holes, not completely stripped heads.
If properly installed, a Helicoil is a permanent repair, many aluminum automotive heads come with them factory installed for durability.
If you have a gasket type plug, then use a Helicoil, if it's a taper seat plug, then you need to use a tapered seat insert. Other than that, your pulling the head, welding up the hole and re-tapping new threads.

I've used Helicoils on many, many motors over the years, and never had an issue. The key is in tapping a clean hole, and properly setting the Helicoil.

 

[dingbat]

Re: stripped plug thread kit--reviews?

This is one of the jobs best left for the experts. I've welded up more Harry Homeowner attempts at head repairs than I care to think about.

 

[reelfishin]

Re: stripped plug thread kit--reviews?

This is one of the jobs best left for the experts. I've welded up more Harry Homeowner attempts at head repairs than I care to think about.

Same here, the best one I saw was an old big twin with Form-A-Thread and a ratchet strap wrapped around the power head to keep the plugs in. The guy even took the time to carve out a custom wood saddle for where the strap came across the plugs. It held the plugs and wires in place. For some reason it didn't work, the strap kept coming loose or falling off and the thread glue didn't hold.
I had another guy that retapped his 6hp Evinrude head to take two 18mm spark plugs, I guess that way his pickup and outboard could share the same spark plugs.