In October 2021 I downloaded the PDF file for the service manual as well as the color electrical diagrams from the Kymco.AT web site (the link posted by NorWeWa). It is free. Sometimes it does help to have the printed manual but I don't mind using the PDF file version. It is the official Kymco manual.
When I was communicating with KymcoUSA in January 2022 (this year) I was told by their technical manager that they were attempting to get the manual published from Cyclepedia. Looks like this might be the result of that. Earlier this year it wasn't available from Cyclepedia. Hard to tell if this service manual has all the same details as the official OEM service manual from Kymco. Kymco.AT is the Austrian equivalent of KymcoUSA and has a lot of manuals in English ready for download for free. The Cyclepedia manual looks to be an aftermarket manual but as I said it is hard to tell if the same level of detail, aside from pictures, is provided as in the PDF. OH, and the OEM Kymco SM does have some drawn pictures, which are actually rather clear and show good detail, but it also has actual photographs also to show many details more clearly and complement the drawn pictures.
My experience with aftermarket manuals is rather dismal. In the past every manual that was not an official manufacturers manual that is used in the shops has been missing significant details in the print. Chiltons manuals for some cars I've owned did really well at providing the details. Haynes manuals were terrible, leaving out at least 25-40% of the details needed to do full maintenance for some vehicles I've owned. But usually I just stuck with Helms manuals for my Honda and Suzuki bikes, and GM cars, since that is the same manual used in Honda, Suzuki and GM shops.
I will keep this Cyclepedia link in mind should I decide to get the printed version. Having both the OEM manual and this Cyclepedia manual might be good for cross referencing.
PS- there is one error in the PDF service manual for the heated grips controller. This was pointed out to me by the KymcoUSA tech guy when he sent me information for my warranty repair in January. On page 9-52 of the Kymco PDF SM the part number that is shown for the heated grips controller is wrong. Possibly an old/early PN that was replaced by an updated improved part. The correct part number for the controller is 3650A-LGC6-E00. Really only the first part of that is really needed for the right part. KymcoUSA has or had the part in their stock and was able to send to my dealer for warranty replacement in 2 days. Don't know if the Cyclepedia manual shows the right part number but something to check. Just FYI.