HELP I need some help identifying my 850 midnight special.I just aquired this bike.the vin is 4h2000071.What does this mean.My local yamaha dealer says the vin means nothing.I dont know what model it is.Is it an xs850?How does the choke work.should you lift it to turn the choke on?Does it have point or electronic ignition?One article said the xs850 had a wider chain,but mine is shaft drive.Help!