I have scored a 1999 bayou 300 for free. It has been setting for years (2) but it was too good to pass up. I have found the usual problems, dirty tank ,clogged pitcock, gummed up carb. etc. I also noticed a oil leak. I lifted the front of the quad up high so I could get a good look at what is going on. I wiped down the case and found something im not sure about. I found a hole in the case at the front and down low. It does not look like it was hit or damaged from riding. The hole is about the width of a penny and about half an inch long, it is located where the case halfs are put together. I thought it could be a vent of some kind but to me it seems to be to low. It would get full of mud and water. I haven't put any money into the quad yet so now is the time to answer this question. Thanks for any help.