I ordered these a while ago since mine are F****d too.
https://www.Eblag.com/itm/M1-6-M36-Helicoil-Thread-Insert-Repair-HSS-Tap-Select-Size-Q3067-ZX/152660365989?ssPageName=STRK%3AMEBIDX%3AIT&var=452195974927&_trksid=p2057872.m2749.l2649
https://www.Eblag.com/itm/12PCS-Select-M1-6-to-M9-Stainless-Steel-Helicoil-Thread-Repair-Inserts-Q3355-ZX/152700734699?ssPageName=STRK%3AMEBIDX%3AIT&var=452306460207&_trksid=p2057872.m2749.l2649
Havn't got them yet though.
Would this be usable.
https://www.Eblag.com/itm/Oil-Pump-16-Teeth-Qmb-139-Qma-For-ATU-City-Star-50-4T-2009-2010/113378762652?hash=item1a65e69f9c:g:yBcAAOSwyUFb7u9W:rk:60:pf:0
As said by Jonny1bump ally is to prefer as you would get petrol and ethanol on that part too.
Probably could do them in PETG, but a CNC setup to do 100's in Ally is the way to go.
I can ask too.