Jump to content

crankcase vent return line


docc

Recommended Posts

Looks like dried gasoline.  Must be sloshing into your tank vent or dribbling some in there on fill ups.

Perhaps I can stop filling the neck well up into the tank and see if this improves or abates. Maybe it only occurs after a fill up and that's why it has been so sporadic.

Link to comment
Share on other sites

If you put your finger on the bottom of the butterfly shaft on the l/h throttle body you may also find where "spooge" is coming from. Raw fuel leaking from the shaft and dripping onto the starter cover and then the ground.

 

Ciao

Link to comment
Share on other sites

 

Looks like dried gasoline.  Must be sloshing into your tank vent or dribbling some in there on fill ups.

Perhaps I can stop filling the neck well up into the tank and see if this improves or abates. Maybe it only occurs after a fill up and that's why it has been so sporadic.

 

As the tank heat soaks from the engine after you park it post tank fill they will often pass some fuel out the vent docc. Try topping right up and not so full and see the difference if any with regards to "spooging"

When I refitted the tank after I put in the cam gears I kinked the vent hose. First indication was after the first ride I went to park the bike and the front fork leg hit the tank to the point where I couldnt lock the steering, both sides. I fixed the vent line and the tank stopped expanding and all was good. Amazing the tank would stretch on each side at least by 1/4 inch due to the pressure and heat rising from the engine.

 

Ciao

Link to comment
Share on other sites

 

 

Looks like dried gasoline.  Must be sloshing into your tank vent or dribbling some in there on fill ups.

Perhaps I can stop filling the neck well up into the tank and see if this improves or abates. Maybe it only occurs after a fill up and that's why it has been so sporadic.

 

As the tank heat soaks from the engine after you park it post tank fill they will often pass some fuel out the vent docc. Try topping right up and not so full and see the difference if any with regards to "spooging"

 

Ciao

 

Will do. Odd that it is relatively new behavior. It seemed to have started after I completely emptied the tank to measure the trapped fuel on the right side.  Yet, I thought maybe it is a characteristic of the fuel formula I've been running. Dunno, but it is a nasty, oily spooge. :bbblll:

 

It occurred to me that the Guzzi gods are taking it out on me for how this turned out . . .

IMG_2679.JPG

Link to comment
Share on other sites

  • 2 weeks later...

Taking a cue from my GB500 crankcase vent and carb overflow traps, I built a drainable trap for the V11 tank vent/ overflow.

 

GB:

IMG_7819.jpg

 

V11 Sport:

IMG_7823.jpg

  • Like 1
Link to comment
Share on other sites

Does the line vent to atmosphere higher up?

That wee rubber vent/overflow line (not the braided crankcase vent return) comes from the two nipples on the underside of the tank, one being the (right side) tank vent that is O-ringed to the fuel cap and the other (left) the tank overflow.

 

Originally, the overflow had a tip-over (one way) valve, but mine is binned so it is actually open to atmosphere at the top and not sealed by the closed cap. Instead of my venting going through twenty feet ( I kid you not! :o ) of 1/2" fuel line to a couple charcoal canisters, mine is Y'd into the overflow, so technically that is also open to atmosphere above.

  • Like 1
Link to comment
Share on other sites

Yeah, I though you wanted the overflow vent line open to air. I seem to recall that some V11 gas caps vent in the cap, but I did not think the USA versions did that. So you need to have somewhere for air to get back into the tank as fuel is pumped out. It isn't just an overflow but a vent to allow air in to replace the fuel being used.

I could be wrong, but that is common practice.

Link to comment
Share on other sites

Yeah, I though you wanted the overflow vent line open to air. I seem to recall that some V11 gas caps vent in the cap, but I did not think the USA versions did that. So you need to have somewhere for air to get back into the tank as fuel is pumped out. It isn't just an overflow but a vent to allow air in to replace the fuel being used.

I could be wrong, but that is common practice.

That makes sense. The tank vents through the cap to the right nipple. Original US V11 then involve the Rube Goldberg twenty-feet-of-hoses-and-two-canisters that I recall had a vacuum pulled on them from the vacuum taps on the intakes.  Seems there was also the nefarious "tip-over" valve that was sensitive to orientation. With an open vent, like mine, I suppose it can push out or pull in as necessary.

 

The overflow drain under the cap is not in the sealed section of the tank and drains fuel spill, or water that might blow or fall in there, to the left nipple.  In the factory configuration, the two systems are fully separated. I'm thinking my vent actually works better combined with the drain and open to atmosphere. We discovered early-on how vulnerable the original system could be to "tank suck." :o

Link to comment
Share on other sites

  • 1 month later...

At this point, it is clear that "whatever" has been dripping under the back of my sump is not the "Crankcase Vent Return Line" as the topic is titled.

The results of the foot powder spay test were misleading.

Today, I finally got to ride after the Sport sat 7 weeks. Rode about 50 miles and fueled 4.3 gallons, being careful not to fill into the neck. Spooge Trap was empty after a long lunch with the guys, and again after another 23 miles for a visit.

Another 60 miles home, and there it is. :bbblll:

IMG_8069.jpg

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...