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fuel petcock on V11/Lemans


Steve G.

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I've got my bike at the shop getting the gearbox looked after. It is stripped of most things for winter cleaning. It is the first time I've actually looked under the tank to see what Al is talking about with his idea of a crossover.

And there I spotted the reason my bike sometimes quits on me. Let me confirm first from someone who knows better. On the underneath of the tank on the left side is first the low fuel sender unit and plug, and then right beside it there is the fuel on/off automatic petcock. On the right side of the tank I would assume is the fuel return unit. And of course way up underneath in the tunnel of the tank are 2 overflow outlets [only one of mine has a drain off hose on it].

So, the automatic fuel petcock wires, on inspection, are barely hanging there, with one of the two appearing to be basically separated right where they go into the epoxy plastic. I guess the wires have been dangling around in the wind [this is the first time I've taken the tank off] and after 22,000kms are giving up. In my eye not a very well engineered set up, but one learns to look beyond these things with a motorcycle you so enjoy.

I guess there are 3 ways I could go about this. 1, I could somehow fix the wires, somehow digging them out from the epoxy and saudering them. 2, replace the silly device by either warranty or my wallet, or 3, replace it with a different type of fuel shutoff.

I've looked back on earlier threads, I seem to remember something about installing a proper manual fuel petcock, either an inline one or one made into the body of the old automatic one. Could not find anything.

Anybody got any ideas?

Ciao, Steve G.

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I've got my bike at the shop getting the gearbox looked after. It is stripped of most things for winter cleaning. It is the first time I've actually looked under the tank to see what Al is talking about with his idea of a crossover.

 

 

 

Let me take your questions in order :D

 

And there I spotted the reason my bike sometimes quits on me. Let me confirm first from someone who knows better. On the underneath of the tank on the left side is first the low fuel sender unit and plug, and then right beside it there is the fuel on/off automatic petcock. On the right side of the tank I would assume is the fuel return unit.

 

Yep, you've identified everything correctly! :thumbsup:

 

And the "fuel return unit" is your fuel pressure regulator that returns fuel from the EFI loop to the tank.

 

 

And of course way up underneath in the tunnel of the tank are 2 overflow outlets [only one of mine has a drain off hose on it].

 

Also correct. If your bike still had it's evaporative cannister emissions system(sounds like it's long gone ^_^ ) you would need both of these vents. But with that system gone, only one is required for venting and/or overflow.

 

That being said, you should cap the unused nipple, or run a drain line from it down under the block... one or the other. Otherwise if you overfill your tank, or for some reason slosh gas up out of the neck of the tank, that open nipple will happily dump the fuel right on top of your hot engine from under the tank :o

 

 

So, the automatic fuel petcock wires, on inspection, are barely hanging there, with one of the two appearing to be basically separated right where they go into the epoxy plastic. I guess the wires have been dangling around in the wind [this is the first time I've taken the tank off] and after 22,000kms are giving up. In my eye not a very well engineered set up, but one learns to look beyond these things with a motorcycle you so enjoy.

I guess there are 3 ways I could go about this. 1, I could somehow fix the wires, somehow digging them out from the epoxy and saudering them. 2, replace the silly device by either warranty or my wallet, or 3, replace it with a different type of fuel shutoff. 

  I've looked back on earlier threads, I seem to remember something about installing a proper manual fuel petcock, either an inline one or one made into the body of the old automatic one. Could not find anything.

Anybody got any ideas?

                                                                          Ciao, Steve G.

 

 

Yep, this is a well known problem on the early V11 Sports. I believe Guzzi stopped using the electric petcocks sometime around late 2001, as the 2002 models all come with the old manual petcocks.

 

As you describe, due to whatever forces end up fatigueing them, the wires on the electric petcock tend to work themselves loose, and often short out.... causing intermittent fuel starvation.

 

The solution? ....replace it with the Guzzi manual petcock.

 

Just give Moto International in Seattle a call. For whatever reason they've seemed to always have had one of these in stock when I've called, and they got it to me within a week. I think the cost was about $45.

 

This is just one of those variables one should cheaply, and easily, remove from the mix by replacing the part. It will put your mind at ease once this is done, so I heartily recommend this modification :thumbsup:

 

al

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Guest geezerx

 

...  If your bike still had it's evaporative cannister emissions system(sounds like it's long gone  ^_^ ) you would need both of these vents.  But with that system gone, only one is required for venting and/or overflow. 

 

That being said, you should cap the unused nipple, or run a drain line from it down under the block... one or the other.  ...

 

al

Al, I'm not 100% sure about this but here's my take. Both lines opened to ground is desirable. The one (I think left) is a drain line for any fluids that might end up around the filler neck. On my bike that would be rain water that seeped under the gas cap and into the filler neck area and then drained into the tank when I opened it to fill up because the left drain line was blocked. :o And the other line would be the line that relieves pressure internal to the tank.

 

I'm doing the lefts and rights from memory. :wacko: My bike is currently in the shop for recall work.

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Glad you mentioned this as it is another part of the stupid question that I was too afraid to ask. I assumed the two tubes in the tank are vents and or drains. One has a rubber tube attached where it exits the bottom of the tank, which indicates that it fuctions as an overflow drain. After removing my tank, I wasn't sure which side had the tube attached to it: right or left outlet/inlet. I think the left. Where the tubes attach to the steel ring inside the tank filler, one side (left) has a brass insert in it, one doesn't. Is this standard? Does one side function as an overflow and the other as a vent? The content of the posts above seem to say this is the case. I would be glad if someone can confirm which is which.

 

2002 model

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The left is the overflow and the right is the vent. Neither should be capped ( ecpecially the vent!)

 

When my carbon cannister set-up mysteriously appeared in a box on the shelf , I "y-ed" the vent and drain together and groomed the routing behind the starter to zip-tie to the engine oil return line on the back of the sump.

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The left is the overflow and the right is the vent. Neither should be capped ( ecpecially the vent!)

I thought I better do the proper thing and actually go look in the tank. It was a bit dark, so I struck a match to provide some light.... er no...

 

I looked in the filler – and my previous description was not exactly correct. The left side has a hole flush with the surface, through which can be seen the brass connector for the 'tube'. The right side has a raised 'turret' where the tube terminates. This fits your description: that the left side is the drain and the right side is the vent.

 

Dear, dear, certain readers of this forum with a more robust approach must be giggling, or crying, at these posts that are obsessed with the minute details of Guzzi petrol tanks –– as they pour another can of Fosters into their fuel tank and guzzle another pint of best premium unleaded down their throat.

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Guest geezerx

The comment "both lines opened to ground" from my previous post was surely an unfortunate choice of words. :homer:

 

I was thinking in the context of "not plugged" when posting. As Docc's, my tank's vent and drain are each routed with drain line, although I didn't think to "y" them into one line.

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My '02 Le Mans came without cannisters or anything connected to the left vent. Since this is just a water drain, I guess it does no harm dropping down over the motor. Of course, I never overfill the tank -methinks a Y-setup might be a good addition. :luigi:

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...  If your bike still had it's evaporative cannister emissions system(sounds like it's long gone  ^_^ ) you would need both of these vents.  But with that system gone, only one is required for venting and/or overflow. 

 

That being said, you should cap the unused nipple, or run a drain line from it down under the block... one or the other.  ...

 

al

Al, I'm not 100% sure about this but here's my take. Both lines opened to ground is desirable. The one (I think left) is a drain line for any fluids that might end up around the filler neck. On my bike that would be rain water that seeped under the gas cap and into the filler neck area and then drained into the tank when I opened it to fill up because the left drain line was blocked. :o And the other line would be the line that relieves pressure internal to the tank.

 

I'm doing the lefts and rights from memory. :wacko: My bike is currently in the shop for recall work.

 

 

Well, not to be contradictory :P ... but since I've had my tank complete apart, upside down, drilled a hole through it, hooked and unhooked innumerable times, in my living room with wrenches and fittings stuck into it... :lol:

 

If you look actually in the tank, you will see that they both come up through the tank identically, and terminate at brass fittings flush with the neck in similar locations..... both drain vent/lines are essentially exactly the same ^_^

 

It is true that in their stock configuration, one is acting as the "vent" and one is the "overflow", but in most post-stock configurations that people perform to combat vapor lock or tank suck, these vents no longer perform these distinct functions.

 

So the application and significance of their function is directly related to whether or not one has the emissions crud still attached, and/or has the red nipple still attached to the "vent" side.

 

As stock, the only difference is that one is "plugged" from the factory with a red rubber nipple inside the neck to vent through the cap(right hand side), where the other is open and flush to the neck to vent fumes and overflow fluid. But on many bikes this red nipple is removed to combat "tank suck", as well as having the emissions lines and carbon cannisters removed. So at that point the dual vent/drain lines are redundant, and in fact the left "drain" is acting as a much more effective vent.

 

Rain water is also drained through a hole in the tank under the pad at the nose of the tank(pre 2003 bikes).

 

If you have the red rubber nipple removed already on the right(original "vent") you could conceivably plug either vent/drain line, but the left is the more effective to leave open I believe.

 

Or you could just do as Docc suggests, and just "tee" both drains/vents together and have one line.

 

Bottom line, you should have both vents either draining under the bike via a line, or plug one... not leave the nipple under the tank open to potentially dump fuel on the engine :o

 

al

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My '02 Le Mans came without cannisters or anything connected to the left vent. Since this is just a water drain, I guess it does no harm dropping down over the motor. Of course, I never overfill the tank -methinks a Y-setup might be a good addition. :luigi:

 

Just to be clear, neither the left nor right is "just a water drain". While it is true that both vent/drain lines are outside the filler neck/cap periphery, and water "could" drain through them... it is also possible, especially for the left vent/drain(since it doesn't have that rubber nipple/turret ever) for overfilled gas to drain as well :o

 

So both should have lines, be "tee'd" off, or one or the other plugged, but only plugged under circumstances where the emissions are removed, as one wouldn't want to exacerbate tank suck.

 

 

BTW, I'm not advocating plugging either vent nipple necessarily, just advocating not leaving either unterminated such that fuel could dump on a hot engine if one spills gasoline around the neck during filling.

 

al

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Guest geezerx

Al, the gromet on the right line in my tank is still in place so the lines I think in my application still perform their seperate functions. And thinking in that context, I brought up not plugging either nipple.

 

Hey, do you suppose those gromets are color coordinated to the bike. I have a black gromet and my tank is black. :lol:

 

One thing I can't be sure of from memory is on the right side line, when the gromet is removed, does the hole then exposed drop into the top of the molded drain tube or directly into the tank?

 

Guess I could wait and check when I get my bike back but by then I will probably have forgotten to look. :blink:

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Al, the gromet on the right line in my tank is still in place so the lines I think in my application still perform their seperate functions.  And thinking in that context, I brought up not plugging either nipple.

 

Hey, do you suppose those gromets are color coordinated to the bike.  I have a black gromet and my tank is black.  :lol:

 

One thing I can't be sure of from memory is on the right side line, when the gromet is removed, does the hole then exposed drop into the top of the molded drain tube or directly into the tank? 

 

Guess I could wait and check when I get my bike back but by then I will probably have forgotten to look.  :blink:

 

...well, I dunno about color-coordination, as my bike is Champagne and my "nipple" was red :lol:

 

 

Anyway, both vents are connected to identical tubes that run through the tank. If you look into the tank through the neck, you can see them. They are white plastic tubes on either side of the neck.

 

BTW, I mentioned earlier that both of these tubes look quite fragile, and in my case I can clearly see the brass fittings through one of mine, and it seems kinda scary. So be careful around them. You wouldn't want to knick or compromise one, as you'd dump your tank of fuel. The manufacturer of the tank really should have routed them differently to protect them :unsure:

 

 

Anyway, to answer your question, no the right side doesn't vent/dump into the tank if you remove the rubber nipple. It dumps directly into the right hand side vent tube.

 

Both vents/drains are identical, and are just tubes that terminate flush with the top of the tank, with threaded brass fittings on either end.

 

The tank actually vents through the cap(but not to the atmosphere normally), which is why there originally is that red/black nipple to create a circuit for the fumes to go up through the cap(when closed) then back over and down the vent tube. Keep in mind that originally this vent tube is connected to the manifold vacuum via the EPA cannisters, as it's a "sealed system" sucking said fumes back into the circuit for combustion.

 

This is why if you have removed the EPA gunk, and vacuum lines from the throttle bodies, it's irrelevant which vent/drain line is used if the rubber nipple is removed. If the rubber nipple is not removed, you need both as the right will still be venting the tank, and left will be the drain/vent.

 

If the nipple is removed, either drain/vent can vent/drain the neck/filler area.

 

Again, a lot of people remove the nipple to combat tank-suck, as apparently this helps to some degree, but I'm not sold on it.

 

al

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...slight clarification/correction.

 

I just went out and took a close look at the gas cap assembly, and thought I had better clarify something after re-reading my posts....

 

Looking down at the tank at the gas cap assembly from the riders position(to clarify right and left), the right vent has the raised black metal "turret" on the filler frame that was described earlier that the red(on my bike) rubber nipple up UNDER the gas cap fits into for the vapor recovery/vent function. These two parts work together to form a closed vapor recovery circuit for the emissions system when the lid is closed. I don't know if this was clear earlier.

 

And the left is flush with the tank top for venting/draining of overflow as mentioned before.

 

If you remove the rubber nipple from up under the cap, you increase the ability for the tank to vent very well in case one of the vent lines plug or in the case where the vapor recovery emissions crud is still active, protects from tank-suck by proving a backup pressure relief/equalization path through the left drain vent.

 

Anyway, as described earlier, the functions are still the same as noted, but I just wanted to clarify the "black turret" versus "rubber nipple" description so that no one was confused.

 

All in all, the left vent is the "catch all" vent/drain line. So if you had to pick one to plug, the right one would be the one, but you'd have to remove the rubber nipple from up under the cap to vent the tank.

 

Hope that helps ^_^

 

al

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Hi Al,

Thanks for the help on the fuel petcock. I talked to my dealer, and they seemed to believe that the manual petcock is integral to the newer system with the "in the tank" fuel pump. They did however report it as a claim under warranty, and should know by Thursday afternoon p.s.t. from Italia whether it will be covered.

I managed to stick a couple wires into where the old ones were, and the unit does still work. What would happen if there were no petcock at all there, just leaving the fuel on all the time? I can see this being a problem with carbs, with lazy float jets, but fuel injection? I could just gut all the gear out of there, and just have the body of the petcock.

When you say "manual petcock", do you mean it as having an actual lever like older bikes?

If this thing is not covered under warranty, I'm going to try to fix it. Maybe run a couple screws into the epoxy right where the wires exit, and fasten wire ends to the wires, then copious quantities of tape so the bloody wires don't wiggle around in the wind.

Ciao, Steve G.

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Hi Al,

Thanks for the help on the fuel petcock. I talked to my dealer, and they seemed to believe that the manual petcock is integral to the newer system with the "in the tank" fuel pump. They did however report it as a claim under warranty, and should know by Thursday afternoon p.s.t. from Italia whether it will be covered.

 

 

 

 

 

....awesome another clueless dealer <_ honestly src="%7B___base_url___%7D/uploads/emoticons/default_wacko.png" alt=":wacko:"> Apologies if I am starting to sound cynical, but jeezus, the things they tell customers when they don't know the right answer(including my dealer half the time :rolleyes: ).

 

Sorry, but they seem to be a bit confused Steve. Just tell your dealer to give you the "manual" petcock from a 2002 V11 Sport/LeMans. It looks just like the electric one you've got, except instead of wires, it has a knurled aluminum knob on the bottom for manually opening/closing the petcock when removing the tank.

 

 

Let me see if I can answer your questions in-line:

 

 

Well, first, there is no petcock at all for the in-tank system, just quick-disconnect fittings that close/seal when disconnected. Snap-on, snap-off B)

 

So they are totally off-base here :rolleyes:

 

 

I managed to stick a couple wires into where the old ones were, and the unit does still work. What would happen if there were no petcock at all there, just leaving the fuel on all the time? I can see this being a problem with carbs, with lazy float jets, but fuel injection? I could just gut all the gear out of there, and just have the body of the petcock.

 

I don't know if you could rig the now broken electric petcock to fail open all the time reliably/consistently :huh2: But if so, it is a non-issue operationally as the system is a looped fuel-injection system with a pressure regulator at the other end. So fuel will not continue to flow anywhere unless the pump is pumping up the EFI loop beyond the 3Bar limit that the regulator opens. And even if it did, it would only circulate back into the tank ;)

 

So having an open petcock on an EFI system is not a problem.

 

BTW, this is exactly how the manual petcock works. It is on/open all the time, unless you are servicing the bike and removing the tank, and need to keep from spilling fuel everywhere ^_^ ..then you crank it closed.

 

 

When you say "manual petcock", do you mean it as having an actual lever like older bikes?

 

Well, sorta.. maybe I should go out and snap a photo. But it's very similar to your electric unit, but instead it simply has a knob on the bottom that you screw clockwise to shut, and counter to open. You leave it open all the time, except for when removing the tank. It does not have any reserve function, nor do you need to operate it in between running and parking the bike like you may have had to do on older carb'd bikes. The EFI makes it impossible to leak down.

 

 

  If this thing is not covered under warranty, I'm going to try to fix it. Maybe run a couple screws into the epoxy right where the wires exit, and fasten wire ends to the wires, then copious quantities of tape so the bloody wires don't wiggle around in the wind.

                                                                          Ciao, Steve G.

 

Oh gosh... don't do that Steve :huh: IMHO jury rigging it is just asking for more unpredictable performance :unsure:

 

My suggestion:

 

1) Don't let them give you another electric petcock, warrantee or not. It *will* just fail again over time.

 

2) Call Moto International in Seattle, and tell them that you want the manual petcock for the V11 Sport/LeMans, as used on the 2002 bikes. They'll know exactly what you are talking about, especially if you tell the story about "why".... it's about $45USD, and if past experience serves, they'll have it to you in about a week :thumbsup:

 

This is a very common problem, and is why Guzzi ditched the electric petcock in 2001-ish. No dealer IMHO should be unaware of this, and if they are... well... sheesh <_>

 

Good luck! Hope that helps :)

 

al

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