Where abouts is the rattle coming from? Front or back of bike? Engine? Shocks? What...

If it's only happening while you are moving and at between 3-4k revs, then it's obviously a component that only moves when the bike moves. Possibly the wheel bearings or something.

I know it's not recommended, but put the rear on a stand and put the bike in first and slowly go up through the revs and get a friend to check where the sound is, or get them to do the throttle and you try to find the sound.

It can even be something stupid like mudguard mounts, or pads in the calipers, unless we get better information.

As Jashdown said, that's how I solved my rattle problem. Be careful, put it on a rear stand and with the engine on put the bike in first and let the clutch out. It'll run under it's own steam and you should be able to figure out where the noise is coming from. If it's internal, put a screwdriver tip against the exhaust, engine etc and put your ear against the handle.

When I put my bike on a stand and ran the engine, to make it didn't fall/vibrate off, I put a cable tand around the paddock stand support and something on the bike (I think it might of been the swingarm I used) to stop it moving left/right.

okay ill try that its just extremly hard to pin point the noise as i can only really hear it when its moving slowly and also when it heats up it calms down a bit its mainly when its cold

did you find the cause?