Metal on metal sound

Hello,
I have 08 wr250x with 2000km. Recently I start hearing this metal on metal sound only when I accelerate, it doesn't happen when I break or ride in neutral.
I had changed both tires, but this noise was there before that. My chain is lubricated and I have no idea what it could be.

If your chain is too loose and the chain slider is worn on the under side it's probably the sound of your chain eating into the swing arm pivot.

My stock chain was trashed by 8K miles and sounded miserable... so being well lubed doesn't necessarily mean it's in good condition.

He's only got 2000 kilometers though....I'd still check that, but I'd be shocked if that was the noise.

I'd wonder about a dragging brake pad maybe?

The bike is a 2008 with only 2000 kilometers.

Try riding in a parking lot with no helmet on and see if you can isolate the noise.

Engine? Drive train? Front end?

ok, I took few pictures...

I took off plastic from front sprocket and there was a lot of gunk, could be plastic. I adjusted my chain, it was a little loosen, cleaned that junk and used some wd40 ( I know I shouldn't use it but I have nothing else, I will lubricate with yamaha stuff on Saturday) then I took a quick ride and it seems like that metal noise is gone :)

Should I worry about that black plastic junk? or now when my chain is properly tighten it will be ok?

That gunk could have come from the chain chewing into the top of the chain slider. On mine, it has chewed into it a bit but it really hasn't changed much in thousands of miles since. May want to keep an eye on it.

I was also wondering if you have the stock rear sprocket with that black ring that sits close to the teeth.

WTF?

Are you setting your chain to the 2008 spec or to the correct tension spec?

The 2008 tension spec is way too tight and will chew up your slider in no time.

Check the underside of the slider, that's where it generally wears through and starts eating metal. The little clean edge on your chain side plates suggests you're at least wearing the slider if not the metal.

chain slider pictures


Chain slider wear is normal.


Excessive wear is not.


See pictures of old and new sliders in link above.

Pokey wrote:

WTF?

Gollum, please let Smeagol come out and play.

You need to ditch that piece of Yamashit sprocket cover and get the sandman part.

I guess it was all caused by loose chain and not enough lubrication. I drove today into work 5km each way and it was fine.
This is my first motocycle, and now I try to keep closer look on my chain in the future

thanks for good advises guys

If you have a 2008, with the black rubber gaskets on the rear sprocket, they will squeak and squeal bad if they get a little dry.

motokid wrote:

If you have a 2008, with the black rubber gaskets on the rear sprocket, they will squeak and squeal bad if they get a little dry.

yes, it's all stock 2008, thanks for advice, I will make sure to keep it lubricated

I scraped both of those stupid rubber gaskets off the front and rear sprockets. Noisy and annoying.

Coop wrote:

I scraped both of those stupid rubber gaskets off the front and rear sprockets. Noisy and annoying.

Are you the one who did that with a chisel while the sprocket was still on the bike??????

That's a good idea, but I used a razor scraper with fresh blade. Sliced right off.