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Pcv system not working. Open the oil cap/ dipstick and it hisses at me. What's going on?

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I noticed today that my oil cap/dipstick hisses at me when I open it up to check my oil. For some reason the oil system is being pressurized. To the point i had to crack open the oil cap to relive pressure on the way home as it was pushing oil past the front cam cap on the valve cover. I did just do the 3x3 mod and a fcr 39 carb. Did the lack of vacuum from me opening up the air box screw up my pcv system from properly working or could I have something else going on? Also notice my brand new Mobil 1 oil is bubbly in the frame reservoir. Thanks in advance for any input.

Edited by sumosquid

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You probably pinched one of the vent hoses.  I suspect the hose from the oil/vapor separator (black box) to the air filter intake boot.  Bobby oil is normal.  The oil return pump mixes in a lot of air into the oil.

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You probably pinched one of the vent hoses. I suspect the hose from the oil/vapor separator (black box) to the air filter intake boot. Bobby oil is normal. The oil return pump mixes in a lot of air into the oil.

Just pulled the tank and fairing double checked the lines, readjusted one of them and made sure there were no kinks yet its still pressurizing the oil system.

Should I try hooking the suction line that goes to the carb boot to a stronger vacume source, like one of the vacuum ports on the intake manifold/head?

I can ride it for just a couple of minutes then unscrew the cap and it will hiss at me. If I open it all the way the oil cap/dipstick will pop up at me its under so much pressure.

Edited by sumosquid

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Dunno what it is, but id get it fixed asap, boiling/pressurized oil, not a good situation.

Happen to know any common issues/causes or anything I should look for?

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Happen to know any common issues/causes or anything I should look for?

Wish i did,   Noble/E marquez will eventually get you sorted,     i just now that pressurized oil is very dangerous, (for both you and the bike)  it will force itself into places. 

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The oil tank is vented to the engine top cover.  The top cover is vented to the oil separator.  The oil separator has a drain to the cam chain tunnel that will also vent the motor.  The oil separator is vented to the air cleaner boot that connects to the carb.

 

It is not a positive crankcase vent system.  There is no vacuum or valves.  No, you can not connect any vacuum to the vent system.

 

Do you have the original breather system intact?  

 

Remove all the hoses and make sure they are unobstructed.  Verify the oil/vapor separator (black box)is not obstructed.  It has 3 nipples and baffles inside, no check valves.  Blow air in any of the 3 nipples and it should exit the other 2.  Verify the nipples on the engine top cover are unobstructed. Verify the nipple on the oil tank is unobstructed. Verify the nipple on the air boot is unobstructed. Blow some air into the oil tank thru the filler and verify the air comes out the breather nipple that connects to the motor top cover. Someplace you will find an obstruction in a hose or nipple.

 

When you are all done you should be able to blow air into the oil filer hole and have it come out the air boot to the carb.

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Thank you so much for explaining the pcv system on my DRZ. I pulled everything apart and found a vacuum cap had found its way inside the elbow that connects to the rubber intake boot. Have no idea how that found its way in there but I'm glad that its fixed. Just hope the excessive pressure didn't cause any permanent leaks/damage. Thanks again! I'm going riding :)

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