Gentlemen,
Kohler is now replacing Kohler Plus. The new system just went live. So if you just need visitors access login to https://kohlerpower.com/en/engines. All current registered dealers are being upgraded to the new system and they will send you a new temp password and link to the new system. Just to note those worried about the .it suffix the website is in Italy and it is a secure HTTPS website. Just got mine and already login and reset to new password.
The new provides access to the diesel engine along with the global gas engine look-up and service info.
Note from Kohler email:
Please, note that the Global Parts Lookup will sobstitute Gasoline Parts Lookup named “Kohler PLUS” which will be turned off on December 31, 2021.
substitute is misspelled but I think that is just a translation error by the Italians.