blueto, as the others have said sounds more like a clutch drag problem than anything terminal.
If you're not already doing so, run an open cover - keeps it cooler, cleaner, for longer. If you're dedicated to closed covers, then from time to time and especially after prolonged thrashing remove the clutch pack and clean all the friction and drive plates, check the condition of the basket, (notches from the plate tangs promote drag and other problems) and the security of the centre nut, (if this comes loose clutch centre moves out enough to contact cover and give drag).
PS.
F*$k the neighbours, your rockers are way more important, ensure you warm the bike thoroughly before any 'undue 'stress is put on it.
Good luck.
