Hi Spada, my nsr had a similar problem when the bloke b4 me had it and it was spark plugs, they are hard 2 find but here's some tips; if you can get a hold of a multimeter, set it to 20K or 20 000 Ohms and put one lead on the spark plug electrode (black tip) and the other on where the lead connects, the reading should be between 3K and 12K ohms if it reads higher, then the plug is stuffed or on the way out, go to a KTM shop they use the same plug as NSRs otherwise they're really rare. Hope this helps ya mate c ya.