Topic: Oil Cap Blowing Off After a Few Minutes of Riding. Pressure gauge reading 100 ps

[StrangeBrew]

Hi everyone.

Having a problem with my oil cap blowing off after a few minutes of riding. The oil pressure gauge is reading close to 100 psi.  Coming off my oil tank is a braided vent hose with what I believe must be a pressure relief valve at the end. I'll include a link to a picture below. The vent hose has always been set up like this without any issue. What is that thing actually called at the end of the braided vent hose? I'm guessing it is defective and no longer opening to release the pressure in the oil tank.

Thanks in advance for any help

Picture Link  https://im1.shutterfly.com/media/47a7db01b3127cceef7c986281af00000030O00EYtmLhwxctge3nwU/cC/f%3D0/ls%3D00609188106120170520214823312.JPG/ps%3D50/r%3D0/rx%3D720/ry%3D480/

[754]

How much oil is n it . Did you add any oil without running the motor ?

[StrangeBrew]

No oil added since last oil change about a month ago. Problem just started yesterday. Do you know what that object is at the end of the braided vent line? I've never seen one before. It has to be some type of pressure blow off, or why else would it be on the line?

[754]

Must be a chopper , Santee maybe?, dont know.about the vent looks like checkvalve ?
Your outer oil line though looks like a big kink, maybe causing the problem .
Should have 3-4 qts oil.

[StrangeBrew]

Yes, it is a chopper, but I'm not sure who the frame is by. I will straighten out that oil line and see if that helps. I put 3 quarts of oil in it at the last oil and filter change, about a month ago. I haven't added any since.

[Bodi]

I suggest removing whatever that metal thing is and see what happens. The scavenge pump empties the sump ... and then it can only sick air. With a nice coating of oil on the rotors it is probably a pretty good air compressor. That air has to go somewhere and the vent line is where... and that weird metal thing is attached to the vent line...
No clue what it is, or why the vent line isn't connected the usual way to the engine case nipple.

[StrangeBrew]

Yeah, I thought about just connecting the vent to the case nipple like you mentioned.  I've had the bike about 5 years and have made no changes to it. That's why I can't figure out what would suddenly cause this issue.  The problem has to be in that part at the end of the vent line. Maybe it's a check valve or something that's no longer opening as it should to vent the oil tank.  I'll pull it off and see what happens.

[ekpent]

  Check the valve cover vent/hose also for blockage. Don't ask me how I know that can be a problem also. Doubt you have a stock oil tank. On most early years a stocker has two hoses, one to atmosphere and one to the nipple at the back bottom of the crankcase.