Ominous chirping sound from my S40

 

Lately my S40 (aka LS650 belt-drive Savage) has developed a chirping
sound which seems to be coming from the rear wheel. It starts about
40 kph (25 mph) and is worst (ie, loudest) at about about 55 kph.
Above 60 kph it seems to diminish.

The noise is somewhere between a chirp and a scrape and it sounds
awful unnatural, as if something is wearing itself to pieces.
It happens only when there's power to the rear wheel. If I pull in
the clutch and coast the sound stops.

I've examined the drive belt and the rear sprocket teeth and found
nothing unusual.

Any ideas what's going on, or what I can do to find out?

TIA, Sean_Q_
'99 FLHTCUI / '06 S40 / '81 CB750 AMEN chopper / various projects

 



Look at the sides of the belt to see if one side is shinier than the
other side.

If so, the nut holding the front sprocket may have loosened up.

There is a soft metal toothed washer that is supposed to hold the nut
and keep it from loosening up. But the washer is made of soft steel
that will fret and wear the teeth out of the center, allowing the nut
to loosen up.

Also, you might want to check the rear brake drum to see if there is a
lot of brake dust build up, and lubricate the operating cam while
you're inspecting the rear shoes.