New homeowner so I invested in a Honda HRX217HYA with the GCV190cc engine. Iv'e been busy with school and work and never thought to change the oil until this weekend. The mower has about 50hours on the original oil that I put in when unboxed it. So I didn't change the oil after 5 hours like the manual said, and when I drained the oil out today it was a thick brownish color, and it had a slight metallic color to it. I refilled it with 12oz of Mobil 1 Full Synthetic 10w-30 and then mowed the back yard. It performs the same as it always has since day one. I'm just worried I may have shortened the life of the motor...thoughts?