I bought the 750K2 harness from PartsNmore for my own bike. It has the correct-for-K2 round plug for the keyswitch, but I have changed mine to be the better K3-K6 style switch with the rectangular plug and larger contacts. So, I must change that plug before I can install the harness. Other than that, it is a good harness: I usually recommend this switch conversion in any case, because the little bullet contacts in the round-plug versions of the K0-K2 bike were a little too small for the bike's loads. It always burns up the contacts on the RED and BLACK wire circuits, over time.
I have another [personal] hard rule that I use in all wiring harnesses for these bikes: I unwrap the harness and check the crimps where the BLACK and GREEN wires join together, for quality. I also run an additional (20 AWG) GREEN and BLACK wire along the entire length of the harness and plug it into a spare BLACK and GREEN at the headlight end, and ground the new GREEN one to the under-seat ground bolt. The new BLACK one gets joined to the harness at the BLACK wire joint to the voltage regulator under the left side cover. Then I re-wrap it all so it looks nice, but I also make my own drop-out sites for a perfect fit to my own bike.
This prevents any tendency to heat up the tiny splice crimps in the harness over time: I plan to ride mine a long time, still, and this approach has prevented any melted wires when the little bullets might corrode, or crack, or split, etc...
