Oil consistently going into airbox

[KeepUrStickOnTheIce]

So I am in the process of selling my 06 Venture. I used it very little during the 3 years I've owned it. I did an oil change last year and rode it about 80 miles after the oil change with no issues of oil coming up through the airbox. I've started it maybe 6 times in 2026 but just rode it around the yard to get the engine up to operating temp. No issues with oil in the air box. Now of course I have a buyer and its puking oil out none stop (see video). I've taken the separator valve off and cleaned it.

I've read several posts and ruled out - overfilled oil reservoir or machine was not tipped over anytime recently

Any ideas?

20260129_143829.mp4

drive.google.com

 

[MrSled]

I believe there is a check valve in that line that goes to the air box from the oil tank. It could be sticking.

 

[MrSled]

I looked at you video, that little rollover valve looking thing is the problem. Its sticking and not releasing crankcase pressure.

 

[maim]

x2. had to clean one on a vector before. if memory serves, i used wd 40 to flush it out.