Question on fluids

[Motorgod0]

Hello. New guy here. First time 4 wheeler owner. This may have been discussed somewhere but I can’t seem to put in the right words to do a proper search. Hoping someone can help. I have a 2000 Yamaha big bear 400 2WD. There is what appears to be an oil fill hole next to the pull cord. The cap has no dipstick.  What fluid goes in that and how do I drain it? 
*the other side has a dipstick for the oil. I don’t want to put something in that could cause an issue. Thanks in advance. 

[Gwbarm]

The hole next to the pull cord is an inspection hole for timing you can look there to set it to top dead center. The dipstick hole is where you add oil. There is a large nut underneath to drain the oil there is a spring under it so dont loose it. The  oil filter is under a cover with 2 large lines going from oil cooler held on by 3 allen bolts

[Motorgod0]

Thank you Gwbarm. Should there be fluid in that inspection hole? 

[Gwbarm]

Yes there will be oil in there but nothing you can measure check your oil with the dip stick.

[Motorgod0]

Thank you Gwbarm. I appreciate the info. Have a great day