The screws retaining the Neutral sensor switch (NSU) are known to be either loose (finger tight) or to loosen themselves off with time and miles. This happens not because the screws aren't properly torqued at the factory, but because the plastic NSU housing shrinks from heat and thus eases the torque of the screws.  In some cases, an entire screw (or even both)  have backed out and fallen into the engine, often being picked up with the next oil change on the sump plug (magnetic) or in the oil. There is no real sign that this is happening except for the loss of or a flickering neutral light. The potential for a screw to end up in the gearbox and destroying an engine is very real and this is an issue any owner should attend to sooner than later to check the screws and secure them.
For this operation it is necessary to either drain the engine oil or lay the bike over onto its left handside.  Before you can remove the engine cover you will need to remove/disconnect the following:
  • Bashplate (if you have one)
  • Engine oil filter cover and filter
  • Rear Brake pedal
  • Oil line banjo
  • Clutch cable/arm

  • Remove cover bolts and place in such away that you know which ones came from where as they are of different lengths. 
  • Pay particular attention to the bolt circled as it has a special sealing washer in that location
  • With a bit of luck, the clutch cover gasket will come away intact and not tear, otherwise a new gasket will be required
  • Note the locating dowels still in place on the clutch cover - do not lose these !

  • In the case you damage the gasket coming off or if you wish to have a replacement on hand just in case, the Suzuki Part number is:    11482-32E00

Removing the clutch pack is optional but I prefer to in order to more easily access the NSU and do a proper job
  • A clutch holder tool may be necessary to remove clutch pack
  • Place parts aside and stack the plates in the same order and direction as they came off to ensure correctness on reassembly.
  • Before touching the screws to remove them, test their tightness by finger (just for interest sake)
  • Unscrew the screws noting how loose or tight they were
  • Leave the NSU housing in place - there is no need to remove this.
  • Clean down the screws of oil 
  • Apply some blue loctite to threads
    • NOTE: be careful to use blue and not red loctite. The use of red will render the screws unremoveable in the future without the application of heat, which may in turn destroy the NSU switch and housing.
    • Some owners have also tie wired the screws but I think that is overkill
  • Reassemble and ride.

  • The rear of the clutch of the clutch sleev hub contains the drive gear for the oil pump. The oil pump driven gear if fibre and can be seen in the photo to the left (orange in colour). When placing the clutch sleev hub back onto its spline, take special care to make sure the teeth mesh with the oil pump driven gear. If you don't, when you do up the clucth sleeve hub nut, you may crush some of the teeth which will result in no drive to the pump and subsequent seizure of the cylinder head/cams.