I did an oil and filter change yesterday, so I'll check them for bits. What would I be looking for on the pistons?

You're chances are you wont find nothing... i dropped the oil from my bike last week and it came out clean... so im completely lost as to whats causing the problem with both our bikes...

Im going to be taking my bike down to the nearest bike shop next week. Will see if they can tell me whats going on by just listening to it... (i dont have the money for them to strip it ect..)

Adam.

Are you still riding yours?

Nah mines off the road atm, bugging the hell outa me though as I wanna tax and test it tbh.

I'm wondering whether I should risk riding mine. What do people think?

Depends on if you're going to be going anywhere important and if you have either AA, RAC or Greenflag Cover...
Im covered by greenflag through my bank (Natwest) so if my bike was t&t'd i might take the risk..

upto you at the end of the day..

Also i've noticed that my cbr has next to no power in it...

Is there vibration in the engine? More than usual?

When bearings go you will usually notice a vibration, which may diminish at high revs.

Does the sound change when you pull in the clutch lever? Or put the bike in gear on the stand (lift the back wheel)?

LHS is only the timing rotor and starter clutch, not really anything you would expect to be rattling.

Best bet is to drop the oil, pull the sump pan off and the two side covers and have a good look. No harm in pulling the cam cover off either. Don't forget metal is a great transferer of sound - think tuning fork, small vibration at one end is a big vibration at the other. It could be something loose on the RHS... like loose clutch nut, worn clutch basket, broken spring, etc.

Things to look for;
Loose bolts - clutch centre nut, timing gear, flywheel etc
Broken or flogged clutch parts, rattly loose basket, broken spring, bolt
Check condition of the primary drive
Look at the base of the cylinder bores (looking up fom the sump) check for signs pistons are slapping on the bore (it should just be shiney with no ridges considering the age of your engine)
Try and rattle your crank in the cases, doubtful this will tell you anything, but there should be no physical movement INSIDE the bearing cases other than spinning (It would have to be flogged beyond belief to rattle by hand)

If you have a long thin piece of metal rod you could place it against the engine and hold the other piece to the back of the jawbone below your ear (or to your ear), you might be able to locate the origin of the sound more precisely. You will also look like a complete tit, so do this when the missus / your mates aren't around. Same theory as a thingamejigger the docs use. Stethoscope. Thats the word.

If a visual inspection doesn't find anything, you need to pull it apart and check for wear......because to me it sounds like something is flogged beyond service limits.

Greggo, whats the chances that it could be the heavy duty clutch springs?
Also what would cause the gearbox to grind in neutral and changing into 1st/2nd?

Cheers,
Adam.

Doubtful it is the heavy duty clutch springs. Although worth checking the condition of the basket/springs and that all the bolts are done up properly.

Define grind? Does the clutch drag making the gear change heavy from neutral to first?

That is generally the clutch plates not releasing properly which is either the adjustment isn't right, or stiction between the plates (they stick together a little). Stiction is no big deal and will possibly go away over time and use a little stiction if normal. If it is making you drag the brake to hold the bike back, you'd need to strip the clutch and go over the push rod, actuation mechanism for wear or damage. It's usually a sign of flogged springs, but not in your case.

Did you replace springs, steels and friction plates? Bent or badly worn steels might cause that too.