I have recently purchased a low hour 1 owner 2007 TRX450ER. So far I like it a lot. After my first long trail ride I noticed some oil in the intake boot as well as on the filter. Upon closer inspection I determined the oil is motor oil and not air filter oil. I did see some evidence that this was coming in from the CCV. This quad seems to have plenty of power and I have not noticed any smoke from the exhaust so I do not think this is coming from worn piston rings. It starts and runs perfectly. According to the seller it still has the original chain and sprockets as well as brake pads so I tend to believe that the hours are indeed low. Very little boot wear on the frame or on the engine covers. So what issues could cause this oil in the air box? I did changed the oil before riding it and refilled with the exact amount specified by the manual (690mL).