I am just about to buy a 2000 773G with 2700 hr. I had the machine on my job site for couple days already,it is running great a lot of power but my only conern is the I can smell some oil it smells like burned oil and the machine has no leaks . I am thinking maybe the motor is burning oil itself. How can I tell if it is. No noticable blue -white smoke. any info please. thanks