If your bike is fitted with an exposed chain, it is necessary to clean and lubricate it regularly, to keep it running smooth and trouble-free. This is because an exposed chain with accumulate a lot of grime when riding, and if too much grime accumulates, it could pose a problem to the transmission system. Here's a video which explains exactly how to perform chain cleaning and lubrication.
(CAUTION: Performing chain cleaning and lubrication involves risk of personal injury. Ensure that the engine is switched-off before proceding, and wear gloves for protection. If your are unsure about being able to perform this procedure, get it done by a professional mechanic)
Given our dusty conditions, it is recommended to clean and lubricate the chain once every 500 kms. Refer to your user manual for manufacturer recommended chain cleaning and lubricating intervals, and for the specified chain cleaning agent and lubricant.
(Video Courtesy: Motorcyclenews.com)