Overtorqued screw and thread repair

[Faber32]

Hi everyone I'd like to help a friend that has overtorqued the screw in picture on his People GTi. It's one of the three oil filter cap screws. After the fact, he told me he removed only a little piece of metal from the threaded hole (right at the entrance), but then he was able to screw it back and close the cap. It doesn't leak oil for now, but the screw it's not torqued with much force, so my fear is that it could get loose with vibrations?
Anyway I was asking myself if in that position is possible to make new threads easily or it is a serious problem. Before taking the scooter to a mechanic and he gets ripped off, I'd like to know better what's the seriousness of the situation. If you have suggestion, please let me know. Thank you very much

[Stig / Major Tom]

I wonder....if you left the cap off, then threaded screw in with fingers....if you'd feel any sideways 'play' on the screw. Indicating damaged threads. Mechanics would probably tell you to re-tap the hole, use larger screw.
It shouldn't be too hard to do it right there.

And, I'd never torque a fitting this small. Hand "Snug" and then stop!!....which I'm sure he's figured out now
Stig

[CROSSBOLT]

Agree with Stig on tighten technique.
Repair by Helicoil the best. Helicoil or similar kit with drill bit, tap and insertion tool, directions included. Probably a thousand videos showing how it is done.

It produces a finished repair that is truely better than the original. The Yager had a similar filter cover arrangement with the tiny 8 mm hex head bolts holding it on. Those were the days!

[mousejunks]

Definitely agree with the above. A helicoil kit is the best solution and not too difficult for a permanent fix.

[Ruffus]

@Faber, as mentioned by Stig, CROSSBOLT, mouse, a HELICOIL insert would be the best and most durable solution.

2nd best would be drill through with 5 mm, retap 6mm, put a longer 6mm bolt

3rd best a bigger (8mm) thread

4th best (if all other fails) driling completely through and put a long 5-6 mm bolt and nut there.

[Faber32]

Guys, thank you very much :-) My fear was that it was impossible the repair, but now he has peace of mind in case it could leak. You're awesome thank you!! :-)