Mate, i've just got a bike with that clicking noise, but its a Sherco 250. It only happends when you blip the throttle if i recall. If this is true with your bike, please say as someone else may find a jtr 160 with that problem but think all the asthetical problems have been corrected. These robbers are smart, they would cover up such big identifying features such as those cracks etc but wouldn't bother with the engine as they arent clever enough to fix an engine and it could be an expensive job so they don't wanna loose money.