http://www.helminc.com/helm/product2.asp?Make=AHC&Model=OFF+&Year=1997&Category=1&class_2=AHC&mk=Honda+Motorcycle&yr=1997&md=Off-Road&dt=Shop%2FService+Information&module=&from=result&Style=helm&Sku=61KZ405&itemtype=N
Bear in mind this book won’t have carb info relating to karting, nor exhaust.
It is 1992-97 which gives the info you need for the 6 speed gearbox.
The 1999 Karting CR125 is a mix of early bottom end (6-speed), ’99 cyl, head, and ignition. (Except in orgs that allow use of the 2001 cyl & head)
You could also order a 1999 manual for an extra 50 bucks, but it’s not really necessary.
http://www.helminc.com
If above link doesn’t work.