How do i know when it's time to get an oil change on my motorcycle?

I've got a 200cc 4 stroke I bought a few months ago and I don't know when it's the last time the previous owner changed the oil. Also, how could I change the oil myself?How do i know when it's time to get an oil change on my motorcycle?for as cheap as it is you should change the oil often, if you just bought the bike and its used change the oil. its just like a car, find oil plug, drain old oil, change oil filter or clean if its a reusable one and put in new oil.How do i know when it's time to get an oil change on my motorcycle?Ya i would just change it anyway, but usually you tell if it needs changed based on the color. If its black, then its all burnt up and needs changed. Go to ur local motorcycle shop and they'll set you up with the correct oil to use.How do i know when it's time to get an oil change on my motorcycle?I change mine every 500 milesHow do i know when it's time to get an oil change on my motorcycle?Get it done anyway. Just search online using the model #.