Bo not over tighten the spring bolts.
I second this, only use the correct torque setting for these bolts, manual says 8nm which is not a lot
- https://archive.org/details/printermanual-yamaha-fazer-fzs600-service-manual-1998/page/n3/mode/2up?q=clutch&view=theater
And I would go so far as to add a small dab of locktight on the threads, someone will correct me if Im wrong.
I would not advise that at all to be honest.
One of my bolt heads snapped as I think due to heat they just weaken over time, a bit like header bolts. When I say snapped, it was very soft, and I was using a torque wrench at the time.
But if that bolt was Loctited in that would've become a far more serious problem.
After a lot of research I found that many people removed their snapped bolts using a variety of instruments without drilling.
Took me about 20 minutes of perseverance and a small Jewellers screwdriver to coax it out, once I realised that when I touched the bolt it moved. The bolts don't bottom out at all so the remaining thread just sits there once the head sheers off.
Once the bolts are tightened up, the springs are very compressed so even at the low torque rating of 8Nm there's a lot of spring pressure holding the bolts in place, so they're not going anywhere. But that's why i would recommend getting new bolts while you have everything apart, seeing as the price is not going to break the bank.
And for a pleasant change Fowlers are the cheapest place to buy them as well. #10 on the drawing (you need 6 of them), and if you're buying springs too stick with the OEM ones, which are #9. Don't be tempted with cheaper versions that are also Heavy Duty springs as they've been tried and tested before and not been found to be necessary.
BEWARE, ANYTHING OUT OF STOCK HAS TO COME FROM ABROAD, AND CAN TAKE 2 WEEKS TO TURN UP!
https://www.fowlersparts.co.uk/parts/4165948/fzs600sp-fazer-5dma-2000-070-a/clutch