Chain/Sprocket problem on 05 YZ 250

[123654]

I have had problems adjusting my chain recently. When I rotate the tire and check the chain tension, some spots are normal, then tighter, then to loose. When I checked it with a tape measure, I got 2in, 1.5in, and 2.5in. Does anyone know what the problem could be? I have a Moose 0-Ring chain, Moose countershaft sprocket, and Moose stainless steel rear sprocket with stock gearing. They have only 4 races on them.

Thanks for the help.

 

[kxmike]

the chain may be stretched out that is why there are some tight spots and loose spots. to see if it is stretched out pull on the chain on the back of the rear sprocket and if it is loose there then the chain is stretched out and you need a new one.

 

[123654]

I dont think its the chain because I tried putting a new one on with 1 ride on it and it did the same thing.

thanks for the info

 

[Jaybird]

Darren, when you take your chain off, are there any kinks in it? Or sections that do not move freely when you flex the chain in your hand?

Try measuring a ten link section of chain. Be as precision as you can. Then measure the rest of the ten link sections of the chain and compare the results.

What you want to do is identify if there is a bad section in the chain. The other chain you tried had been used...and not very likely it is bad yet, but it could also have a bad section.

Did the other chain act exactly as your chain did?
If so, do you have another rear sprocket you could mount up just for checking? It may be that the sprocket is non-concentric. It happens.

Are any of the teeth in either sprocket showing ANY signs of wear?

One thing to consider, hard sprockets like the stainless can eat up a chain fast if you even the least bit too tight on your chain tension. This condition is also very hard on wheel bearings. Every time you land a jump it could be eating things up, if it is too tight.

 

[i_955]

There might be dirt in part of the chain. If you power-wash without spinning the rear wheel you only clean part of the chain. The part that is not clean will be full of dirt therefore tighter/looser/tighter/looser as the wheel is spun during adjustment.

If it is the stock chain it might be time to replace before it kills your sprockets. The OME chains are usually el-cheapo, like the rubber.

The sprocket might be bent. Pull it off, put it on a flat surface and check for true (if it is worth saving). When reinstalling, use a criss-cross pattern, if it was installed using a clockwise pattern it could get crooked. Always blue-locktight the sproket.

 

[pace]

It's not unusual to have tighter spots and loose spots in your chain tension, when rotating the rear wheel. The difference should not be huge, though.

Obviously you want to adjust tension at the tight spot to ensure you don't subsequently bind.

 

[Studboy]

One other thing to check would be your rear wheel bearings. Make sure that there is no play there.