Triumph Scrambler Project: Removing the California Evaporative Loss Control System

While in the process of installing the stage 3 upgrades to the Triumph Scrambler project (more on that soon), I suddenly found the “Charcoal Canister” under the swingarm to be problematic.

EVAP Delete Charcoal Canister MotoADVR

I suspected that the black cylinder hanging off the back of the frame was likely part of the California emissions package; after a Google search, that suspicion was confirmed. Unfortunately, no thanks to the Photo Bucket debacle, I found it significantly difficult to identify the steps and components necessary to remove the superfluous equipment from the motorcycle. After spending a few hours reading and exchanging information on the various forums and craning my head around in all the nooks and crannies on the bike, I put all the necessary pieces together to return the bike to the 49-State standard. For fellow Triumph twin owners, I figured it made sense to publish that process here, lest is be lost to another photographic hostage situation elsewhere.

What is an Evaporative Loss Control System?

As it is specifically related to motorcycles, the fuel tank is vented in order to equalize pressure and properly feed your carburetors or throttle bodies.

EVAP Delete Left Side Throttle Body MotoADVR

Naturally this means that gasoline fumes and potentially minuscule amounts of fuel could potentially make contact with the air, which is apparently extremely offensive to the state of California (after thinking about it, I guess that state does seem to be especially combustible). Thus a system was devised to capture any excess fuel or fumes in a “charcoal canister”, and even pump said fumes back into the intake to be burned off during normal operation.

Why would you remove the EVAP system?

I suspect there are no major side effects from leaving the evaporate system in place, at least for most motorcyclists.

EVAP Delete Charcoal Canister Hose connections MotoADVR

The weight of the system is pretty inconsequential, and for the most part it’s out of sight and out of the way for the average rider. Some folks on the interwebs have suggested that the system could potentially create a “hard running” condition if you’re in the habit of overfilling the gas tank. However, in my case, I’ve successfully submerged the canister on multiple occasions; which I suspect has potentially caused the evaporative system to run at less than peak performance. In short, it’s not required in 49 states and it’s in my way.

Where is the system installed on my motorcycle?

EVAP Delete Throttle Body connections MotoADVR

I am writing this specific to 2009-2016, 865cc, fuel injected, Triumph twin motorcycles, however I suspect you’ll find that this system is mirrored on various other motorcycles irrespective to brand or model. Per my comments above, a tube is run from the fuel “vent” down to the charcoal canister. Two more tubes are ran to a “T” from the throttle bodies and down as a single tube to an electronically controlled purge valve, and then into the canister. Lastly, there’s a additional, single tube run the from right throttle body down to the canister.

How do I remove the California Evap system?

EVAP Delete Vacuum Caps MotoADVR

First, to familiarize yourself with the following steps, I recommend you read the previous description of the system and attempt to identify each of the components I mentioned on your own bike.

EVAP Delete Hose Routing MotoADVR

Some of these items may be difficult to see, you’ll want to remove the seat, and the left side panel from your Triumph to properly follow the route the tubing follows through the bike’s components. Before you get started, I recommend you stop by the auto parts store and pick up at least three 5/32” vacuum caps, along with a few zip-ties.

EVAP Delete Canister cut loose MotoADVR

Once you’ve identified the three locations where each tube connects to the throttle bodies, look under the bike at where each of the tubes connects to the charcoal canister; be mindful that the solenoid valve is mounted above and behind the canister and may be out of sight. I would first start by cutting the two zip-ties that hold the canister to the mounting plate. Once the canister is out of the way, it’ll be easier to take an 8mm socket and remove the plate from the frame. Once the plate is off the bike frame, you can cut the solenoid valve loose from the plate, and disconnect the valve from the connector that runs from the main wire harness.

EVAP Delete Vacuum Hoses MotoADVR

With the solenoid valve loose, disconnect the three tubes from charcoal canister and set the canister and the valve aside. Look carefully at how the remaining vent tubes are run down the left side of the bike, under the frame and up to where the canister was previously positioned. There are likely brackets mounted to the frame to hold those tube in place; these can be removed or re-used if you plan on leaving the fuel tank vent tube in place (which is what I did).

EVAP Hose Connections Upper MotoADVR

Next you’ll want to remove the vacuum tube from the left throttle body; this tube runs to the t-joint to the opposite throttle body. Disconnect the opposite tube from the right side throttle body, and pull the t-joint with all three tubes off the bike; you may need to carefully fish the lower tube from between the air box and the frame. Next you’ll want to remove the final vacuum tube from the right side throttle body; again fishing the tube out of the brackets between the frame and the air box. Having removed the throttle body vacuum tubes,

EVAP Delete Fuel Tank Vent Hose MotoADVR

there will be a larger diameter vent tube running from the fuel tank down to the bottom of the frame. I left this tube in place, as it is run in similar fashion to the way it was installed on my non-California compliant Speedmaster; you may want to zip-tie this tube to one of the routing brackets, just to make sure it stays in its desired location.

EVAP Delete Left side Throttle Body Capped MotoADVR

At this point you’ve removed the major components of the evaporative system. Next you need to cap each of the vacuum nozzles on the throttle bodies with the before mentioned 5/32” vacuum caps. With the throttle bodies properly capped, the bike is once again in proper running order, however I recommend you re-locate the power source for the EVAP system solenoid. I fished that electrical connection back up over the swing arm, and into the left side cover area behind the intake snorkel. Other owners have covered the connector in electrical tape and zip-tied it under the frame; it’s completely up to you.

California Emission Canister Removal MotoADVRAfter re-installing the left side cover and the seat, the bike is ready to ride. Cranking the engine for the first time after removing the EVAP system, you may find that the bike idles slightly differently and the throttle response may feel different. With the changes to the intake system, you may need to adjust the idle knob to get the engine back to the desired idle speed (I usually hover around 1000 RPMS). If you find the throttle response a little sluggish at first, take the bike out for a ride and get it up to proper running temperature. Afterword you’ll need to park the bike and let it cool back down to ambient temperature. California EVAP Delete Complete MotoADVRYou’ll need to do this “heat cycle” at least three times as the ECU is re-learning the throttle map based on the new operating conditions. After about three rides, the bike should perform just as it did prior to the canister delete. It was about 40°F when I did this modification, so that no doubt played a role in the engine being cranky; you may find that your bike behaves no different than it did before you removed the EVAP system. Also note, if you’re considering removing the Secondary Air Injection (SAI), I would recommend you perform the canister delete at the same time if you discover that you’ve purchased a California compliant model (and don’t live in CA).

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12 Responses to Triumph Scrambler Project: Removing the California Evaporative Loss Control System

  1. Kevin says:

    Definitely doing this on my Tiger 800 when I do my oil change this weekend


  2. bill osak says:

    thanks for the effort in laying out the procrdure. however , i am in process of correcting a emission removal job that was done and no documentation. I noticed that the triumph valve solenoid with two wires and ( two tube ports, one at a right angle) is amiss.. one tube if run down to the metal balance tube bewt the 2 carbs. The other is left open and nothing is attached to it..I did notice on a cold start, blocking that tube port, and the idle pulled out, the engine rpm drops and is close to a stall…should that open port be closed or remain open or connected to something else? thanks much..


    • Drew Faulkner says:

      Bill, what model and year? Are you re-installing the charcoal canister?


      • bill osak says:

        sorry for the delay, i did not realize that anyone would respondso quiickly. the bike is a 2005 triumph boneville black. i started this search after buying the bike and noting that the heat difference was too great between exhaust temp. I found that the vent at bottom of right carb needed to be connectqed to vent midway of left carb. that took care of the heat imbalance betw the cylinders. I assumed that i could remove or disconnect the black flex tube that ran to the balance tube betw the 2 carbs. Bad idea…i needed to keep that line open or connected to the solenoid valve. the previous owner had used 4 vacumn caps ..2 each on the carbs and intake manifold….plus the two that i mentioned above to correct the heat disparity. I looked at 3 different you tube videos and all show simple removal which i tried to finish ..however when the tube going from the solenoid to the balance tube was blocked, bike would run as if it was fuel starved at higher rpm. attached to the solenoid or simply left open, the bike ran ok.. something i amiss ..what am i missing about that flex down tube .??


      • Drew Faulkner says:

        Hey Bill, ky apologies, I don’t know the Carb models as well. I’m concerned there may be some vacuum functions being used with those hoses that the EFI bikes do not use. I’ll try to see if my Haynes Manual covers this. In the meantime I would post a thread on and see if someone can share photos with you of the correct setup.


  3. bill osak says:

    Forgot to mention that i am attempting correct removal , the cannister is removed, the 3 way valve at front is not connected to anything.. the only operational item now is the solenoid valve where two ports are open and only the tube to the balance remains


  4. Waldek8 says:

    Hi I need your help. I have a fuel leek in my triumph. Does anyone know how to connect fuel line on that photos? If it’s possible please take a picture how it’s should be connected.


    • Drew Faulkner says:

      Waldek, undortunately your link isn’t working. Ultimately, make sure your gas tank vent tube is hooked up and runs down below the frame. Not sure what else it would be if you’re only messing with the charcole canister.


  5. Patrick says:

    Depending on your countries laws, removing emissions equipment may be illegal. This is the case in the USA. Doing this to a street/on-road bike is illegal. The EPA has recently started cracking down on these illegal mods to the extent that “Off-road use only” is no longer a permitted justification.


    • MotoADVR says:

      Regarding a 2013 Triumph Scrambler, removing the California Evap canister might be “illegal” in California, but 49 state bikes were sold without that system. I’m not a lawyer, nor am I an enforcer of any type of governmental regulation. What you’re saying is a wise warning for more modern machines. As far as this bike is concerned, I do not believe this is illegal in Ohio.


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