Is a Yamaha Raptor 450 a good...
 

...beginner quad? I can get one of these for a bargain This is My first quad though. Is this machine too much for me to handle for my first ATV? I understand this is a racing bike but I don't want to buy a P.O.S. that I will get bored with in a few months.

if you have no experiance I'd say no, but I don't have any suggestions maybe a used blaster.

quads aren't that fast so you should be fine. If your an idiot you'll kill yourself on anything if your smart you could ride a Honda 250r with a Yamaha R1 engine in it and be fine. My first quad was a kawaski kfx 700 with an upgraded exhaust and clutch. It had 53 horsepower (the 450 has about 45) and a top speed around 90 mph (the 450 hits about 75 mph stock). Don't be intimidated because none of these things are very fast stock.