While washing my Quadrunner today I noticed the drain bulbs under the air filter were full of oil. So I took the filter out and noticed about 2 shot glasses worth of oil all together in the bottom of the box. I drained and cleaned out everything. Any ideas on how the oil is getting in the box. Could it be from standing the quad on it's back wheels. I do that occasionally when cleaning it.

 

That is the cause of the oil in the airbox. Anytime a machine is rolled or tipped on end, oil will run into the airbox. The amount will depend on the machine. I have dumped about 4 shotglasses out of my SP500 just from tipping it on it's side.