Motorcycle Repair: Chain, rear axle nut, chain rollers

Question
Hi, Ive got a generic defiant 250cc which is like a Chinese knock down of Yamaha Virago 250cc. Im not sure what the year is, the person I bought it from didnt know either. and my chain some how came off while riding it. Could you tell me how I can maybe loosen the chain and put It back on? my brother said that he thinks that the sprocket is messed up, but I think it looks fine. Thanks.

Answer
Aaron, the drive chain adjustment is critical for any chain-driven motorcycle. Proper inspection, lubrication and adjustment is mandatory, if you want to stay alive on a motorcycle of any size or make.

IF it is a Yamaha copy, then use these illustrations for reference:

http://www.bikebandit.com/houseofmotorcycles/yamaha-motorcycle-xv250t-virago-250...

You need to find something to block up the rear wheel, then loosen the rear axle nut. There are two chain adjusters on both sides of the axle, which draw the wheel backwards, taking up the slack in the chain. You probably want about 3/4" slack in the middle of the chain, but you need to spin the rear wheel and check the chain slack at several points to be sure that the chain doesn't have a "tight spot" which will take up the slack suddenly while the wheel is turning. If the chain does have tight spots from lack of lubrication and perhaps damage to the links, then you need to think about a new drive chain of good quality.

To have a chain jump off the sprockets means someone was really NOT paying attention to maintenance issues. Be sure to check the chain adjustment and oil levels regularly. Buy a can of spray on chain lube and keep the chain rollers looking slightly wet at all times.

Bill Silver