Suzuki 2 Strokes

Since giving my Gt 750 a complete rebuild it has devolped a strange tapping noise which orginates from near the rev counter gear case.
It is really wierd as it only occurs when the engine is hot and idling , when it is running at speed no noise is heard.
Can anyone tell me what it could be, oh yes the cable into the case moves around a bit at idle, the bold securing the drive is tight.
Any thoughts.
jim.

The tacho and waterpump are both driven by that nylon gear inside the left case. Behind the gear is a little metal retainer that is used as an oil dam to help lube that assembly. Maybe that plate is missing and there's not enough oil hanging around at idle, but it splashes up at higher RPM.

I would pull the case, and check the nylon gear, and the tacho drive.


Lane