on the front sprocket, the sprocket moves in and out about 1/4". Is there a spacer that goes in behind the sprocket??
Thanks
Nick

 

Is the sprocket sliding on the shaft? Or is the shaft sliding in/out? The second would be serious.
The first, nope, there isn't a spacer. Just a big washer on the outside where you put the bolt.

 

250r sprokets should be flush with the end of the shaft. Some sprokets will have the spacer made on the sproket and some will come with an extra spacer. It will look like a large washer. If your sproket is flat on both sides you must use the washer or spacer. If your new sproket is flat on one side only, the spacer is built into the sproket. If the sproket that you are putting on sets out pass the end of the shaft you need to remove the spacer on the shaft from the old sproket. When you tighten down the bold it should set flat on the end of the shaft with the sproket.