2011 500 sportsman crankcase vent blowing oil in air box

[Werewolf]

Airbox is getting oil in it from crankcase vent, the engine has 2 cups of oil when I drain it. I drained it out put it back in the reservoir, prime it start it up after a few minutes it starts spitting oil out?

 

[Gwbarm]

My first thought would be ring blow by but that sounds like to much oil for that, i would check the crankcase vent and make sure its not stopped up there is something causing it to build up too much pressure in the crankcase.

[Cj Winds]

Headgasket leaking pushing compression into oil passage

[Werewolf]

Do you think 2 cups of oil in the crankcase is two much

[Kirt]

All Polaris hold 2 quarts of oil. If you have only been putting 2 cups (16 oz) when you change your oil, you have problem.

Check exhaust valve to see if it's set to spec.

Check exhaust pipe to make sure something is not blocking exhaust. People like to pull tricks.

Run a compression test on cylinder, no throttle then wide-open throttle.

[Gwbarm]

Two cups is barely lubing anything im surprized the engine hasnt locked up.

[Werewolf]

My understanding is the crankcase holds about one cup the resivor hole the rest feeding the engine as needed

[Gwbarm]

I wondered about that when you told me 2 cups, i dont work on Polaris so i wasnt sure. So you check the oil at the holding tank and then it goes into engine when running,  That sounds like the way the old Harleys worked. I  didnt know they used that type oiling system. On the old Harleys i understood because no matter how much oil you put in half would leak out.

[Ejwill]

Harley’s have to mark their territory.