Newbie Rider

Thanks everyone for your thoughts. I'm on the same page, that Helicoil repair would likely be best. I'm still not clear what the two separate materials are in the picture: https://imgur.com/a/kX7ZWXS If I helicoil this, I calculate that I'll drill out all the material that makes up the inner ring, and then be tapping new threads into the casing. I'm not sure what this inner ring actually is, whether it's part of the sump, and whether it matters if I drill it out.. Once the screws have loosened up, I can try and take the engine out and apart to find out, unless someone can advise. There's a youtube video of a bloke in India Helicoiling the YBR125, but I can't see the same inner ring on his sump. It's most clear at 2:07: Thanks!

Thanks for your reply Onesea. No, unfortunately the metal was definitely stripped threads… I’ve not heard of gasket sealant before. Definitely worth a try. I bought a new sump plug and was able to hand tighten and give a further quarter turn with a wrench without the bolt slipping, so definitely some grip left but clearly some gaps. Thought doing the Helicoil job would be the most thorough approach but am very unsure about the metal lining!

I did my first oil change on my (new to me) yamaha ybr 125. When I pulled the plug out I noticed a metal coil around the sump plug. It was intriguing but later learned that it was the threads from the case of the engine Clearly they've been striped by the bolt being overtightened. It seems my best option is a Helicoil kit to re-do the threads. However, this YBR125 seems to have a separate metal lining in the sump, which doesn't look thick enough to be drilled out and re-threaded with the Helicoil kit for M12 1.5mm plug. https://imgur.com/a/kX7ZWXS If I drill through this lining and tap into the casing, is that a problem? I can't work out what this metal lining is from any drawings and can't tell if it's on all YBR125s, as I can't see it on pictures of other bikes!! Any guidance would be very appreciated. Thank you!!