I just bought this bike and I just noticed a really bad grinding noise coming from what seems to be the transmission case. I can feel a vibration in the left peg in concert with the noise and it only does this while moving. Just at idle sitting still no noise start moving and its grinding like a whon whon whon noise and it does it even if the clutch is pulled in just coasting down the road. Any advice would be greatly appreciated.....

Sounds like a bad chain.
Put in neutral.
Put on center stand.
Rotate rear wheel and examine chain for kinked links.

Yeah I just went and looked at it I think im just gonna replace the chain and front sprocket the rear sprocket looks good. Could a wobbly front sprocket cause those symptoms and if I change the chain and front sprocket do you think it would clear it up. Thanks

Front sprockets do wobble a little.
A chain with stuck links will make the noise.
Replacing them should take care of it.

Ok ill try that first and ill let you know how it works. Now of I do the chain and the noise persists would you recommend changeing the front sprocket as well ? And thank you for your advice

Now you said kinked links how do I know if a link is kinked or not. Im a car mechanic and sad to say I dont know much about bikes. :-/

Chain: If you look at it, it should lay straight. All links should move easily. A chain is not a motorcycle specific thing. Its a chain - and the same applies wherever you find a chain.

When you change the chain, you should change  the sprockets. They wear together. Often the rear sprocket - because it is bigger - wears much less than the front. Therefore, you may not always have to replace the rear sprocket. Front - YES - always change it. be sure to get the front sprocket with the hub - like 1996 to present is the same. Chain 520 x 110. Get o ring or better. Old chain has to be cut off (OEM chains do not have a master link).

Here's a pix of bad links:

How do I know if the front sprocket has a hub as you say I found several on ebay but I want to get the right one with the hub like you said I just dont know what im looking for exactly. I got a o-ring chain 520 110 link so im good there now I just need to figure out which sprocket to get. Thanks for any advice and info

94-09 model years have hubs, only 89-93 years did not.

Thanks for the info. Ill try these repairs and get back to you to let you know if tgis solves the problem. Thanks and god bless...

Grease the splines on the output shaft before you fit the sprocket, it goes someway in preventing wear.

Thanks all for the info... it was definetly the front sprocket. when I took it off it was so worn it was only like half a centimeter long in the tooth and the chain was so kinked up I could hold it up and it would hold straight out for like 15 links. thanks again for all the info ... saved me a lot of time and money

Can we see pictures? We live for pictures.

I will take pictures . I kept the old sprocket for some weird reason . as soon as I can ill post some pictures on this thread.

 

Yes, but does it com in Platinum? Thats the popular thing now, isn't it?

Dunno? ... Was thinking a suitable suggestion for his kept old sprocket ... Length of chunky men's jewellery chain, front sprocket .. Mega industrial type bling