So far it is just a start up noise and not all the time hot or cold. No failures reported to date. Even the naked bikes which were released in 2021 with same engine seem to be doing it as well.
No and I never have in the past on any Suzuki. I have taken GSXRs straight from the showroom with 5 miles on them and gridded them up for a race. Never a problem. I was under that rpm lawyer talk recommendation for maybe 300 miles then had a trip which required power to keep from getting killed on it. It had plenty of quality heat cycles prior to that. That is not the reason for this and if it is that is weak build quality because I am not the only one hearing this. And it appears it dates back to the 2020 model Katana's with same engine.Just interested to know, did you stick to the 5,500 rpm limit for the first 500 miles and 7,500 rpm limit until 1000 miles?