You are correct, there is a discrepancy with the Haynes & Clymer manuals
Quote: Haynes - K3-K5, 130-135cc SAE oil 10w-30w
Quote: Clymer - K3-K5, 220-230cc SAE oil 10w-30w
I went with the Clymer spec, as the K3-K5 (American only bikes) are not covered in much detail in the Haynes manual.
Alan