Here is where to look, the oil sensor is on the front cylinder head on the left side as you sit on the bike.
The sensor is under the Y-conector that feeds coolant to the heads here....
If you look thru the lower left motormount you can see the sensor and conector.....
Its a bitch to get to even with the motobox but this is wher the prob lies... I had the same deal with 75mi on the clocks.
When the system works corectly you should have a oil light with the motor not running and is should go out a few seconds after you start up. if the wire is off all toghther you will not have an oil light at all after the key is on and the tach dose the dance. When all is working corect you will have an oil light with the key on befor its running.
Hope this helps mate