This generation of Katana is not like photo 13 (which has the old skool Suzuki GS-series engines). The generation of Katana under discussion here is the bubbly-styled full-enclosure-fairing type which has an engine of air-and-oil-cooled first-generation GSXR design origin. Like this
Google Image Result for https://cdn.visordown.com/styles/amp_1200/s3/494_0.jpg?itok=P-SVC72u
What have you done to diagnose the noisy engine ... ? ? ?
If it has a bad timing chain tensioner, the first step is to check the condition of the tensioner, before you touch anything else on the engine. This is an in-frame job. I don't know if you can get at it without removing the carburetors ... possibly. Definitely do this before taking the engine out of the bike.
The shop manual has procedures for diagnosing the tensioner, and for how to reset and install it. Follow those.
If you find during removal that the tensioner was not applying any tension because it has extended all the way out (when you take out the bolts, you don't feel the tensioner pushing further out as you release the last bolt, and you can re-install the fully-extended tensioner without following the tensioner-resetting procedure without feeling like it is pushing against something internal - the chain guide), this means the chain and/or guides are shot, and then, yes, the engine needs to come apart.
If you find that the tensioner was not applying any tension because the internal spring isn't pushing any more, or if it can be pushed shorter by hand indicating that the internal ratcheting mechanism has failed, you need a new one.
If the stock (spring-loaded) tensioner has gone bad, one option is to replace it with a manual one:
GSXR Zone - Cam Chain Tensioners