Ridemalibu Motorcycle Rentals & Tours – Los Angeles CA
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Evap removal from V7III

Discussion in 'V7/V85/V9 Chat & Tech' started by Godfrey, Oct 17, 2017.

  1. Godfrey

    Godfrey High Miler GT Famiglia

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    Todd's been stressing I should can the evap system and its 'vacuum leak' since I started talking to him about the ECU reflash for Racer. Well, this morning, my second test of the ECU map with a stone-cold start on a chilly morning proved conclusively that Todd's work on that is absolutely spot on: Start, fifteen seconds to get a little heat into the cylinders, ride away ... no stumbles, no lean spot, nada. Just perfect. Thanks Todd!

    But, as I returned home a couple of hours later, I noticed that the idle revs were acting a little "funny" and that the throttle seemed a hair "sticky." No idea why, but killing the motor and restarting cured both symptoms. Two miles later as I pulled into my driveway, the sticky throttle sensation was back again.

    On a hunch, I opened the tank and heard a gasp of air, there was a vacuum building up in the tank. Ah hah! the evap can and it's valve were screwing up as I was told.

    I spent a bit of time with the V7III ABS Service Station Manual PDF and finally found the evap system on page 234-237 as "Sistema evaporativo canister". Now I could see where they were located approximately and understand the operation completely. Vacuum line connects to the evap can to draw fumes through the tank breather after passing them through the charcoal. The valve is supposed to limit how much vacuum is applied and vent when it's too much. Obviously, it wasn't working right. A cheap and crappy valve, essentially, is the cause of the problem. But the system is ugly anyway and almost totally unnecessary for the evaporative emissions of a motorcycle.

    Not having much time, I pulled the seat, side cover, and starter cover. Yup, there are the lines from the intake manifold to the canister under the gearbox, there's the tank line with the valve in it. Looking at the flow from manifold to canister, it was obvious how to do the quick'n'dirty: I cut the line going to the manifold and stuffed a blanking plug into it to stop the vacuum leak. I then cut the line coming from the tank vent and going into the canister just above the valve gizmo, and cut the bottom line and the valve off the canister. No more vacuum leak, and the tank now vents to atmosphere exactly the same way my LeMan V tank did ... just a small line leading from the top of the tank down behind the starter.

    Procedure:

    - remove seat
    - remove left side panel (three bolts)
    - remove starter cover (two bolts)
    - locate vacuum tap line from manifold to canister under the gearbox
    - locate breather line with valve connected to canister
    - cut vacuum line and block it (I glued an aluminum slug in place)
    - cut breather line above the valve and below at the canister inlet
    - leave the breather line open ended behind the started ... put a filter on it if you worry about environmental dust getting into the tank
    - replace starter cover
    - replace side cover
    - replace seat​

    You're done.

    note: Another one of those cheap clip nuts broke when I removed the side cover. Glad I got six better quality spares! That's three now... I'm going to pick up another dozen because I see them all over the place on this bike.

    I'll clean up my work next time I get a chance by removing the vacuum line and canister completely and using a good vacuum tap plug, maybe extend the breather line down an inch or two and put a little filter trap on it. But this will suffice for the present.

    I'll see what its behavior is on my run out for dinner tonight.

    BTW: Is this little valve on the breather line what's referred to as the "tip valve"? Or is that something else still? ... Thanks!

    G
     
    Last edited: Oct 18, 2017
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  2. Godfrey

    Godfrey High Miler GT Famiglia

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    Checking my work: Last evening's run for dinner ran about 50 miles or so, up the freeway through dense traffic, a bit of pootling around in town, then back home via a different route up and over the hills on surface streets and a fast blast down the other freeway.

    In all of it, Racer ran flawlessly. Perfect throttle response, excellent power, no "funny" idle, no vacuum in the tank. The low fuel light flicked on about 6 miles from home so I stopped and refilled the tank at the gas station a half mile away on the way in. The second full tank-load ran the same 49.9 mpg and just shy of 200 miles from full to warning. Perfect.

    Today I'll hunt up the appropriately sized vacuum connection cap so I can remove the evap charcoal canister and its vacuum line in their entirety. One less bit of useless junk to clutter up Racer... :D

    G
     
  3. Godfrey

    Godfrey High Miler GT Famiglia

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    I took some pictures while working on disabling the evap can yesterday. Hopefully this will help someone out there... :

    Illustrated Procedure:

    - remove seat
    - remove left side panel (three bolts)
    - remove starter cover (two bolts)
    - locate vacuum tap line from manifold to canister under the gearbox
    evap-001.jpg

    - cut vacuum line and block it (I glued an aluminum slug in place)

    Follow the line and cut it in a convenient place, then block it ... particularly the upstream side that comes from the inlet manifold.​

    evap-002.jpg

    - locate breather line with valve connected to canister
    - cut breather line above the valve and below at the canister inlet​

    evap-003.jpg

    evap-004.jpg

    - leave the breather line open ended behind the starter ... put a filter on it if you worry about environmental dust getting into the tank (but it ain't going to happen... :)

    - replace starter cover
    - replace side cover
    - replace seat
    Hope that's clear ... ask if you have any questions.
     
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  4. JACoH

    JACoH Cruisin' Guzzisti

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    OK, now I am a believer, too. I did the above evap hose mods yesterday, and went for a 150 mile ride today 'cause, well, 70 degrees and sunny. I did the GTRx reflash 4000 miles ago, but today I was amazed, somehow the 2 together, just as Todd said, transforms this bike. It seems smoother, 3500 rpm is now usable where 4000 was minimum before to get it to move in any gear. Now I guess I am just waiting for Santa to bring me the Agostinis.
     
  5. Godfrey

    Godfrey High Miler GT Famiglia

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    Yup. It really works well. Racer is a happy boy, and waiting for me to install the Agos now. :)
     
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  6. Mayakovski

    Mayakovski Cruisin' Guzzisti GT Famiglia

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    Would making this modification require a flash to the ECU to ensure correct running? Also how does making this modification affect your warranty?

    I would think that the company could deny claims regarding the engine as you have disabled/removed certain components.

    Maya
     
  7. kiwi dave

    kiwi dave GT Reference

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    I don't believe this would require any reflash of the ECU, it's only a breather after all.

    But I agree that if you're bike had issues, the dealer might blame the modifications and deny a warranty claim. Mods have to be done discreetly or out of warranty.

    I've just discovered my V7-III Stone has tank suck. Like my Cali 1400, I think I'll just remove the innards of the valve for now, and go the whole hog after my warranty has expired. Unfortunately, I have to do services via the dealer to keep the warranty active.

    On another note, how is the V7-III service spanner icon reset? Is this something that has to be done by the dealer using PADs or similar, or is there a technique using the dashboard buttons like the earlier models?

    I haven't been able to find any information anywhere, and fear I might be in a similar position as the Cali 1400 (until I discovered the service code password).
     
  8. Raven

    Raven Cruisin' Guzzisti GT Contributor

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    For a warranty claim to be denied because of a modification, it has to be proved that the modification was the direct cause of the issue. However it seems that Moto Guzzi will deny a claim any chance they get.
     
  9. GT-Rx®

    GT-Rx® Administrator Staff Member GT di Razza Pura

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    It’s not, it’s an emissions component as it pumps air into the exhaust port.
    Good to know on the tank suck Dave.
    I haven’t yet had a light come on yet and I’m beyond when it should come on. Please post if anyone here has seen one.

    There are long threads here on fueling.
     
  10. kiwi dave

    kiwi dave GT Reference

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    Ha! The Auckland dealer service manager noticed that I had connected heated grips, radar detector and an SAE connector cable directly across my battery on my Griso 1200SE. Each circuit was protected by an in line fuse.

    I was having issues with the battery discharging with the ignition key switched off, making it difficult to start after a week or so of non use. The discharge current could be measured across one of the 30A fuses, but not across any of the smaller fuses. The service manager said any warranty was null & void because nothing is allowed to be connected directly to the battery.

    Where do all these rules come from? Invented by local dealers who can't be arsed lodging a claim I suspect.
     
  11. vagrant

    vagrant High Miler GT Contributor

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    I did the first service on my V7 III a bit early at 750 miles. It's 900 for the 2017.
    I do not remember ever seeing a service light come on and I'm at 3000 miles now. I did reset the shift light at that time and the traction was set to 1. Both were a PITA! So either it doesn't have one or it's connected in with the other two.
     
  12. Godfrey

    Godfrey High Miler GT Famiglia

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    The manual says that the service light does not come on for the first service. Mine certainly hasn't. :)

    My dealer, when I mentioned the EVAP system was disabled, simply said, "You know, that's required by law; we cannot remove it. And it's truly amazing how many customers come in for service and we discover that it's fallen off the bike ... It doesn't affect anything so we don't care." :D
     
  13. Dinsdale Piranha

    Dinsdale Piranha Cruisin' Guzzisti GT Contributor

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    This is confusing to me, in the context of this thread. I thought the breather/canister system was quite discreet from the forced air system you describe in the quote above. I plan to do both when I receive the appropriate bits from you. Are there some common components in the 2 systems? Bear in mind that this my 1st Gutz, 1st FI engine and 1st bike with emissions crap on it, and I've not removed the tank for a looky yet.
     
  14. Godfrey

    Godfrey High Miler GT Famiglia

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    DP, the EVAP emissions canister is a completely different system from the Supplemental Air Injection system. You don't have to remove the tank to see and modify either of them ... see the photos above tor the EVAP system. For the SAI system, you have to lift the tank a couple of inches to reach the bolts and hoses easily, that's all.

    Although they are completely separate systems, they both can affect air/fuel ratios in a secondary way and cause undesirable behavior:
    • The EVAP system can cause lean running if the valve jams open because the vacuum tap it works through is upstream of the inlet valve. It can also apply vacuum to the fuel tank, causing fuel starvation and (in a bad case) oil-can the fuel tank. Essentially in this situation, the fuel pump has to work against the vacuum applied by the EVAP tap, so it could also damage the fuel pump.
    • The SAI feeds air after the exhaust valve to accommodate spikes of overly rich mixtures going to the catalytic converter. This makes the downstream mixture lean out ... in the absence of the catalytic converters' baffling, it causes the mixture to explode in the exhaust pipe and thus the "barking" or "popping" sounds. There's a small reduction in power every time it pops, but essentially since it's happening after the exhaust valve, it's not affecting basic power production. Blocking it off removes the barking and popping ... particularly in the absence of a catalytic converter, where it is completely unnecessary.
    Both of these systems are intended to preserve the life and function of the catalytic converter. The problems they cause are secondary to their function. If you're going to run an exhaust without catcons, there's no need for them. I disabled the EVAP system first to prevent it oil canning the fuel tank, since I noticed vacuum building up in the fuel tank and odd running behavior within only a couple of hundred miles from new. A side benefit of disabling it and removing the EVAP canister is that it's easier to fit a center-lift stand (the Pit Bull item) in order to service the motorcycle.

    After fitting the Agostini mufflers and having GT produce a customized engine map for them, Racer now runs almost perfectly ... The only glitch is the SAI induced popping on overrun. So I'll shortly remove the SAI system: it's totally unnecessary without a catalytic converter to protect.

    G
     
  15. Richard Ducati

    Richard Ducati Tuned and Synch'ed

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    Godfrey,

    First and foremost, thanks for posting pics and writing up your canister removal blurb. I just got a GT tune from Todd and need to do this work. Like you, I'll probably just snip and plug the hose attached to the manifold vacuum port until I have better access to remove the system completely.

    In terms of the tank vapor vent, I'm struggling with why your machine would develop a vacuum on the tank side. Is there no other vacuum relief for the tank? The evap system has a check valve between the tank and evap canister, so there must be some sort of vacuum relief to relieve the vacuum developed due to fuel use (vented cap?). I was planning on just nipping off the hose at the canister outlet for now and removing the section between the canister and manifold, but will be more thorough if the check valve is an issue.

    Regards,

    --Rich
     
  16. Mayakovski

    Mayakovski Cruisin' Guzzisti GT Famiglia

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    Morning Rich;
    I believe if you search around this forum you will find a fair number of posts pointing to the check valve being garbage and failing. I think that is the reason for the vacuum issue in the tank. Gonna do this soon myself, I have the gear from Todd, just waiting for my bikes first service to be done.
    Ciao
    Maya
     
  17. Godfrey

    Godfrey High Miler GT Famiglia

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    Yes, it is the check valve itself that is at issue. That's why I blocked the vacuum tap and removed the check valve. The first eliminates a vacuum leak on the intake, the second allows the tank to vent properly.

    The EVAP system wouldn't function at all if there was a second vent on the tank. then you'd just have a vacuum leak. :)
     
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  18. Richard Ducati

    Richard Ducati Tuned and Synch'ed

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    Understood. FWIW, I thought the evap system was just there to vent positive pressure from the tank due to fuel expansion & sending the vapors into the intake for burning, thus protecting us humans and other species inhabiting the planet from all those nasty fugitive emissions. In my little brain, the presence of the check valve between the tank and canister thwarts any thought that vacuum was to be relieved using this same system.

    Anyway, bottom line is that the check valve needs to fall off in order to ensure that the tank vacuum relief is fully functional....
     
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  19. Godfrey

    Godfrey High Miler GT Famiglia

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    Okay, perhaps a little context will make this clearer for you.

    The EVAPorative Emissions Control System (EVAP) is designed to prevent gasoline fumes from the evaporation of fuel in the tank from going to the atmosphere. EVAP systems should be totally passive and innocuous, similar to the Positive Crankcase Ventilation (PCV) systems that have been in place on most production engines since the 1950s.

    Basically, even when just sitting and doing nothing, fuel in a tank slowly evaporates and fills whatever space is in the tank with a small amount of vapor. For large fuel storage tanks, this can be explosive and very dangerous, not to mention costly if the fuel is vaporizing away unheeded, so they have extensive vapor circulation and recovery systems designed to recapture the fuel vapors and return them to the tank. In motor vehicles like motorcycles, automobiles and trucks, the amount of vapor loss is really quite small on a per machine basis, but given that it is still an output to the atmosphere that can be avoided pretty simply ... by routing it to the intake to be burned with combustion ... it seems simple enough to put a passive system in place to handle it. Automobiles and trucks typically spend a great deal of their time sitting parked, often out under the hot sun, between trips which exacerbates the evaporation problem.

    Fuel tanks also build a certain amount of negative pressure without venting while the machine is running (due to the fuel level being drawn off for the injection/carburetion), which creates MORE evaporative fumes to build up in the open air space of the tank. (...As atmospheric pressure goes down, more fuel molecules can escape the surface tension of the fluid body into the atmosphere...:))

    So the EVAP system's intent is to leverage the vacuum in the intake manifold to draw the fumes away from the tank while the engine is running by applying a small, persistent vacuum to the open space in the tank, and vent the fumes into the intake stream for burning.

    The purpose of the charcoal canister is to scrub any residual output of the tank's fumes, letting charcoal granules absorb them temporarily, while the machine is sitting still. (The flow of air through the canister during engine operation will be towards the intake plenum, because of the vacuum being applied, so the residual molecules are basically recovered and pushed back into the intake while the machine is running.)

    The purpose of the so-called "check valve" (it's not really, as should become clear) is to regulate the amount of vacuum being applied to the tank and make sure that the flow of gases is always in the direction of the intake plenum. So it's not really a "check valve" per se ... which is a one-way flow valve only ... but more of a very simple "vacuum regulator." It's supposed to not allow too much vacuum to be applied to the tank's air space, allowing atmosphere to enter the line between the tank and the valve when the vacuum being pulled by the intake plenum goes over a prescribed limit, while not letting positive pressure push fuel vapors out to the atmosphere.

    Too much vacuum in the fuel tank has two negative effects:
    • Fuel delivery is constrained, since too much vacuum in the tank is making it much harder for the fuel pump to smoothly deliver fuel at the specified pressure to the injector nozzles or carburetors. Ultimately, it could cause fuel pumps to fail through overheating or their own valve failure.
    • The structure of the fuel tank itself is only designed to withstand so much vacuum and, in a high vacuum situation, the fuel tank itself can be deformed by external atmospheric pressure pressing against too low an internal pressure.
    The problem with the EVAP on these bikes is that the check valve (or vacuum regulator) is a cheap device barely the size of a couple of large coins stacked together, and the charcoal canister is actually too small to operate very effectively as well. If you look at these systems on an automobile, for an engine barely twice the displacement of the V7 engine, the charcoal canister will be 4 to 8 times the volume and the vacuum regulator valve typically a similar amount larger as well. The problem is there aren't many good places to put such large components in the tight confines of a motorcycle's engine systems without them also being something of an eyesore. Combine this with the fact that the tiny amount of fuel carried by a motorcycle, and the relatively low percentage of motorcycles left sitting in the sun whilst parked (where static fuel evaporation would be at its worst), in the context of motor vehicles at large, means that the EVAP system on motorcycles at the present time doesn't contribute very much at all to the removal of fuel fumes from the atmosphere. It's hardly a big emissions problem at the present level of motorcycle population in urban areas, or the world at large.

    Meanwhile, the EVAP system, because of its underperforming specs and the fragility of the vacuum regulation device, can actually cause significant harm to the bikes' performance and running characteristics, and can cause costly damage to both fuel pump and tank. It definitely causes some issues with the ECU programming, which has to be tailored to the additional, variable draw of air/fume mixture into the intake plenum.

    I realized there was a problem the day I exited the freeway and came to a stop light at the end of the ramp: The engine first idled roughly and then stalled. Since I'd heard of the problem, I tested by opening the fuel tank cap, and was greeted by a "Pop!" as the slightly bowed fuel tank side panel returned to its proper shape as well as a big sigh as air rushed into the heavy vacuum inside the tank. I rode home and disabled the EVAP before I took the motorcycle out for the next ride. The problem has never reappeared, the bike does not put out any noticeable amount of gasoline fumes, etc etc. :D

    G
     
    Last edited: Jun 13, 2018
  20. Richard Ducati

    Richard Ducati Tuned and Synch'ed

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    Wow. Quite the explanation and understandably a major concern given the level of vacuum you were seeing in your tank. I'll follow your lead and just go to an open tank vent to avoid any possible issues.

    Best regards,

    --Rich
     
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