What Dave meant to say, but I butted in first, was that after you've set the nut by feel you then tighten the nut up to 2.5 Kg.m as it says in the manual.

If I've just replaced the headstock bearings, here's my procedure:

Fit lower clamp to headstock and spin on the preload nut (the one you're talking about) finger tight.

Flip flop the clamp full lock left and right a couple of times just to check smoothness. Should be smooth.

Now, tighten up the nut while sort of flipping the clamp left and right until you just start to feel it tighten up, then give it a tiny little nip more and flip it lock to lock a couple of times. This helps to square up the bearings.

Loosen off and repeat the above three or four times to be sure the bearings are square.

loosen off for the last time and then tighten up to recommended torque, which is going to be a little tricky unless you've got the special tool.

2.5 kg.m is actually quite tight, but this also serves as a mechanical steering damper of sorts (I was told that by Honda men in Japan so blame them not me).

My bike is not done this tight, as when we were setting up race NSRs what we did was to do it up tight as possible by hand, then just nip it up a bit. That's what Dave was talking about with this "feel" thing. This gives a nice smooth, quick to react front end, but you'll have to pay more attention to the bearings as they'll possibly loosen up within not too long. Using taper roller bearings work better than the stock balls with the "gently nip it up" method.

This is how we set the GP bikes up in Japan, so fear not!

The lock nut should be gently nipped up to the preload nut and the lock washer tabs secured.

If in any doubt, follow Dave's method.

One if the reasons that the headstock bearings can feel loose within a short time after replacement is because they weren't fitted squarely. Following the method above should eliminate this possible problem.