1993 DR650, Chain goes from slack to tigh as tire turns

[gtbensley]

Here is what I know fellas. I just picked up a 93 dr650 in pretty decent shape, runs and drives well for the most part. While I was in the process of buying it, the PO was driving it around the yard and got hard on the gas for a second. As he did this the chain came off the rear sprocket and skipped on the hub for a couple seconds.

As he slowed down the chain then found more resistance on the hub and started making an awful grinding noise. We put the chain back on by hand, (thats how lose it was), and figured everything was ok.

Got the bike home and figured I should adjust the chain to speck so it wouldnt fall off again. After I did that now every time the wheel rotates the chain goes from tight to slack.

I have narrowed it down to a point on the chain where it binds not the sprocket. Does this mean I have a kinked chain from it falling off and getting jammed between something?

What would you guys recommend me doing? Does it sound like the chain is my problem?

Thanks, Sorry for the long post.

Oh I forgot to mention, I think the chain came off the first time because the bolt was so lose on the axle the the axle torqued to one side with the acceleration.

[Yossarian™]

Sounds as though the chain is old, and has some stiff links. I doubt lubing it and working the lube through would solve the issue; I'd personally opt for replacing the chain (and possibly sprockets.)

[Lesharoturbo]

I am no expert, but I will add my $.02.

It sounds as if the rear sprocket was misaligned whenthe PO hit the gas causing the chain to jump the sprocket or the cahin had some stiff sections from sitting too long. What you didn't say is if the chain was new(ish) or how long the bike had been sitting. If the chain is old or if the bike has been sitting a while (especially outside), the chain can have tight areas that may be fixed with a good light oil or diesel soaking and working back and forth. If this does not help, replace the chain.

YMMV

[gtbensley]

The chain and sprockets do not look all that beat but they dont look brand new either. The bike has not been ridden much in the past couple of years. I will try taking it off and soaking it in diesel and also try to put the sprocket back on and make sure its strait.

[Kiwi Tinkerer]

Seems most likely that your chain is worn out. With a bunch of bad links on one part of the chain it would go loose and then tight.

[955616846]

Originally Posted by gtbensley

The chain and sprockets do not look all that beat but they dont look brand new either. The bike has not been ridden much in the past couple of years. I will try taking it off and soaking it in diesel and also try to put the sprocket back on and make sure its strait.

Nooooooo! Replace it. Stiff links can also indicate broken or damaged pins.
When you have replaced the chain (and sprockets) dissect the old one to see for yourself.

[gtbensley]

Where might one recommend me pick up a chain? I am very uneducated on chains for the most part. I will most likely pull the old one off and soak it in diesel but I think replacing it wouldn't be a bad idea either sometime soon.

[raptortrail]

You have a bad chain-repace it.

[gtbensley]

I cant seem to find anywhere what size my chain is? Its a 93 so I believe it must be a 520 correct?

[955616846]

Search JT Sprockets online catalogue.

http://www.jtsprockets.com/

For a '90-'95 DR650

Chain is 520 / 114 links. Choose a DID O-ring or X-ring chain for maximum life.
Stock front sprocket is 16T - JT pn JTF437
Stock rear sprocket is 42T - JT pn JTR828

You will need all three. Your sprockets will also be shagged and putting a new chain on the old sprockets will destroy it very quickly.

Find a dealer who will get these parts at a decent price.

[955616846]

BTW, stiff links can be symptomatic of broken pins amongst others. They'll often hold on for a while, but should be replaced immediately. If it ever does let go it will ruin your whole day.

If your existing chain is an O-ring chain (probable) and you manage to free it up by soaking in diesel then you have... 1. Stuffed O-rings ...and 2. No grease in the links.
Don't even clean chains with diesel (or petrol). Go your hardest with WD-40 or use the manufacturers recommended solvent, kerosene.

[gtbensley]

Good to know thanks, Ill start looking for new chain and sprockets.

[Crazy_Dave]

DR650’s are geared very high, now would be perfect time to remedy that. I went with a 15/45.
BTW DuPont chain saver will be your new best friend.

[gtbensley]

Looking for a good chain and sprocket combo now. I am not sure if I want to go as low as that. I was thinking 15/42.

Can I mix the type of manufacture for sprockets front and rear or should I stick with the same company front and back?

[gtbensley]

Thoughts?

http://cgi.ebay.com/ebaymotors/Chain...item4aa3b51e55