I have an 08 sportsman 500 HO EFI bought new in May 08. I have roughly 16 hours as I have only used this for hunting and plowing this year. Just went to ride with some friends when all was well until the bike made a chatter then stopped. We found the oil reservoir located behind the front left wheel was split and had drained out. I assume the bike has a safety feature that shuts it down when oil pressure drops. We towed the bike to camp and removed the oil tank, called to see if we could get one and it wasn't stocked. Knowing i had to replace it we tried sealing it so the day wasn't wasted. We sealed it and added oil and the bike fired back up but has a knocking at idle and upon acceleration. Has anyone else had trouble with this oil reservoir? Also, why don't they make it out of plastic or place someplace with more protection? Does anyone think I could get Polaris to warranty this? I appreciate any help you can offer.