hi, i'm wondering if anyone knows of a common problem with the wr's with the top or at least it sounds like it's coming from the top end. i was in second gear, in the woods, on and off the throttle alot then i started to hear a rattle so i stopped to listen properly then it got really loud, really quick then i shut the engine off. i have since started it just for a second or two to let a couple of mates hear the noise and it runs fine and ticks over fine but with a loud rattle and a lot of vibrations through the frame. its regulary serviced and the bikes had about 4 hours use on the new oil. i could do with some tips or advice before i take the engine out. thinking about doing the work myself unless it's a lot more complicated than i think then i'll have no choice but to pay to have it fixed. any kind of advice would be helpful (and please no advice to leave it alone as i'm on a hugely tight budget and i need to try and fix it myself) thanks for reading. ps the timing is still correct and the chain has the right tension and the valve clearances are ok.