Installed a UM 4 qt oil tank on my 05 Predator ran bike 3 or 4 times since install today saw oil leaking out of dipstick but when I removed air box lid it was full of oil looks like it came from breather hoses any ideas??? thanks

 

Had a similar problem with my Hawkeye. Found 2 things. If oil level is at the top and you have the power on and sustained for a while, a vacuum is created in the airbox and it pulls oil from the high oil level up through the breather/filter in the airbox. Others have said it is common for theirs to do it also. Polaris must expect them to do it and that is the reason for the sump and drain in the airbox.