Another C50T Making A Noise

My 2008 c50t is making a noise that I can’t quite pinpoint yet.

I’ve tried searching through this forum and have found where I think a similar thing is being asked about, but either never really answered or it turned out to be something else that I don’t think is my bike’s problem.

When I get up to about 30 mph I start hearing a
“Grr…..Grr..Grrr…..Grrr..Gr….Grrr..Grrr..Grrr” sound.

I’ve now taken the bike out for several short rides around county roads and a couple of 50 mile rides.

I ride with a 3/4 helmet and hear the wind so at first I wasn’t sure if it was just windshield noise, but it seems to be increasing in volume and frequency. There’s definitely something going on.

About this particular bike:

• It has about 6900 miles on it.
• A previous owner (2 back from myself) did not protect this bike well from the elements. It has a few rust spots, but it still looks pretty good from a few feet away.

What I’ve done to it so far:

• Changed engine oil & filter.
• Replaced air filter with a K&N filter.
• Put in new NGK spark plugs.
• Drain & replace radiator coolant.
• Change final drive oil.
• Ran some Berryman B-12 Chemtool through a tank of gas.

I’ve read a good bit on here about the driveshaft splines and know I need to get some moly paste and order a seal & circlip and check them out very soon.

The sound doesn’t seem like it’s coming from the driveshaft though. At first I thought something with the water pump. It’s not running hot. Fans cycles ok. Shaft seems to be tight and working alright.

Any thoughts what this could be?

Any threads you can point me to?