I have used theseThese things
https://www.ebay.co.uk/itm/Spark-Pl...2349624.m46890.l49286&mkrid=710-127635-2958-0Yes I considered those but I'm not sure if since some Muppet already helicoiled it, will there be enough material to fit one? Wurth time sheets do a 'fat sert' that is bigger and designed for just the this situation, but a time sert' kit is not worth buying for one job. However I just thought...I could try the cheap insert, if there isn't material I could build it up with the braze rod and then insert...aha! I wonder if the braze rod would even flow to the insert to braze it in place? Hmm, that would be impressive, unlikely but impressive! TBF I'd be ecstatic if I could just get it to stick to the the cylinder and not melt the cylinder on the process!
![IMG_20211113_221509.jpg IMG_20211113_221509.jpg](https://cdn.imagearchive.com/arboristsite/data/attachments/625/625316-b5d9ec463cb0d3e7dc322891c92ca4c1.jpg)
With relative success... Relative being the operative term there as I've had a couple that didn't work as they should. As frank suggested it's not a bad idea to swage them from inside the cylinder if you can & I'd definitely recommend using loctite.
I did a 288xp the other day that had the helicoil unwind on the plug, wound one of these straight in to replace it... was a little tighter than usual but worked all the same.
I made a small reaming tool to get them to recess flush, would work well to correct a damaged plug sealing surface.
![IMG_20211113_221551.jpg IMG_20211113_221551.jpg](https://cdn.imagearchive.com/arboristsite/data/attachments/625/625317-633462b3072d55f873c908c6cdd20945.jpg)
![IMG_20211113_221616.jpg IMG_20211113_221616.jpg](https://cdn.imagearchive.com/arboristsite/data/attachments/625/625318-89ef57a70c887fac21ba9e83395a3ab2.jpg)