The swingarm on the 21 is different so you can not use the new method on the old bike.On my 21' model at 40 mm downwards pushing ,between the pins and 32mm before the end part of the plastic guard, it gives 20mm up and down free play. Mine at 46mm makes a lot of rolling noise. Also measure at different parts of the chain as they differ a little and keep the measurement at the tightest spot .I will grant you, the ‘21 manual has a weird way to measure your chain slack. I don’t know why they had to go and change a procedure that’s been used for decades.
Here’s the XSR manual (and I’m pretty sure the FZ/ MT manuals are identical):
View attachment 166941
So you can see they are calling for 5-15mm of slack in total, which is insane. That’s way too tight, because that’s measured with no load on the rear of the bike (shock topped out), and as the swingarm travels through the part where it’s in line with the countershaft (front sprocket), it’s going to be super tight.
I like my chain to have about 25-35mm of slack, so if I measure it the way the ‘21 manual shows, I would get this measurement:
View attachment 166942
85mm from the bottom of the swingarm.
So if I push the chain upward and measure, I get this:
View attachment 166943
50mm from the swingarm. This means my slack, or free play, is 35mm, which is about the max of my preferred range.
What this means is that if I wrote my chain slack measuring procedure the same way the 2021 manual does it, I would say “Push the chain downward and measure from the center point of the chain link to the bottom of the swingarm. This measurement should be 80-85mm”
Do you see how that would be the same as saying 25-35mm of slack, and not 5mm?