chain clicking on cog !!!!!

[Ixion]

Take a look at the "valleys" between the teeth (must be a proper technical term for them, buggered if I know what it is ). They should be the same on the "down" side as the "up" side ; ie symetrical. In the picture they're not.

Granted, I wouldn't call it badly worn, not enough to replace in its own right. But best to replace it if the chain is being replaced.

[MSTRS:Me]

It is worn, and if I was replacing the chain I would do the sprocket too.
The wear may not be apparent but it is like this....left is new, right shows wear caused by chain grinding at the rear edge of the tooth. Acceleration is when this happens - the effect is slow but cumulative. A new chain put on this would stretch/distort/whatever to bed into the malformed teeth.

[Stopper Dan]

Sprocket wear
Pic 1 shows wear that would necessitate replacement
Pic 2 shows typical 'trailie' sprocket showing wear at the extreme end

My sproket is probably halfway between both pics.. New sprokets me thinks.

[MSTRS:Me]

My sproket is probably halfway between both pics.. New sprokets me thinks.

Yes. And as mentioned, you will get the best price if you go with a kit. I paid $360 for a kit on the 1100. The old chain was roooooted and being a 532 pitch, which is little used these days, meant I needed to convert to 530 pitch.
532 chain on it's own is over $400.

[Pixie]

Rear wheel needs alignment.

[MSTRS:Me]

Rear wheel needs alignment.

How do you figure that?

[Pixie]

If the rear sprocket is not in line with the front (as it would be if the wheel was out of alignment) the chain is forced to bend horizontally and will jump from side to side as it's grip on the teeth lets go.
This will make a click sound.

[MSTRS:Me]

Now I see what you mean. There would be obvious wear on the side of the sprocket teeth tho. And the misalignment would be major - ie tyre would be touching swingarm on one side. Clicking is way more likely to be a tight spot on the chain, which is what alerted me to my chain needing replacement.