California emision canister
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Intermediate
Joined: Feb 2009
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From: Northern California
California emision canister
I had to take the gas tank off my 08 fxdl in order to repair a broken gas tank bracket weld.
With the gas tank removed it was easy tracing the hoses to and from the emissions canister. It has two hoses coming from the left side, one hose going to the gas tank and one hose going to the carburetor (just after the filter). The other hose comes off the right side and just stops between the bottom side of the gas tank and the top of the front cylinder head. No wires connected anywhere to the system.
I decided now was a good time to lose the emissions canister but before I take it off I'd like to know exactly what it's supposed to do and how.
I've always assumed it was a vapor recovery system. Based on that assumption it appears like the system sucks hot air (vapor?) from the top of the front cylinder head, through the canister back to the carb (doing the sucking) and the gas tank (also doing a small amount of the sucking in order to equalize the pressure in the gas tank).
I'm just guessing about these mechanics, please correct me if I'm wrong. I plan to remove the canister and all the hoses, then cap off the carb and gas tank intakes.
I'm a little worried about how the gas tank will act when I roll up to a gas pump. Will it spray out misty air when I open the gas cap? If any thing it seems like it might suck air in while opening the gas cap.
Any other problems I should be aware of? I'm pretty sure others have done this.
Thanks in advance for any light you can shed on this issue.
Terry
With the gas tank removed it was easy tracing the hoses to and from the emissions canister. It has two hoses coming from the left side, one hose going to the gas tank and one hose going to the carburetor (just after the filter). The other hose comes off the right side and just stops between the bottom side of the gas tank and the top of the front cylinder head. No wires connected anywhere to the system.
I decided now was a good time to lose the emissions canister but before I take it off I'd like to know exactly what it's supposed to do and how.
I've always assumed it was a vapor recovery system. Based on that assumption it appears like the system sucks hot air (vapor?) from the top of the front cylinder head, through the canister back to the carb (doing the sucking) and the gas tank (also doing a small amount of the sucking in order to equalize the pressure in the gas tank).
I'm just guessing about these mechanics, please correct me if I'm wrong. I plan to remove the canister and all the hoses, then cap off the carb and gas tank intakes.
I'm a little worried about how the gas tank will act when I roll up to a gas pump. Will it spray out misty air when I open the gas cap? If any thing it seems like it might suck air in while opening the gas cap.
Any other problems I should be aware of? I'm pretty sure others have done this.
Thanks in advance for any light you can shed on this issue.
Terry
Stellar HDF Member
Joined: Mar 2006
Posts: 3,124
Likes: 255
From: From Long Island, now in So. Cal
Removing the vapor canister:
The single hose on the right side of the bike from the vapor canister goes up under the tank and doesn't connect to anything it is just a breather hose you can just pull it out.
On the left side of the bike you have two hose's coming off of the canister. The canister is labeled carb / tank, disconnect the tank hose and follow it up the frame to a little vapor valve, remove hose from the bottom of this little vapor valve and remove the hose. This is now your 49 state tank vent, you can also get the 49 state vent hose that connects to the vapor valve and runs up under the tank, it is in the Harley parts catalog (99439-06A) item 13 on page 90 P/N 27296-04A TUBE, VALVE TO ATMOSPHERE and a retaining clip item 7 P/N 10113 CLIP, DOUBLE HOSE.
Disconnect the carb hose from the vapor canister, this line goes up the frame and under the tank to a connection behind the top left side of the air cleaner, it connects to the intake manifold, disconnect and put a cap on the port of the intake. (In the Harley parts catalog (99439-06A) on page 20 they list a cap plug item 21 P/N 90383-98 CAP PLUG, INDUCTION MODULE that might be the one to use.) This hose is difficult to remove, I took off the rubber hose from the plastic tube by the intake and pulled the hose out from the front of the tank and broke off a clip that supports a harness that comes out of the bottom of the tank, but I was able to ty-wrap that harness to another harness under the tank near the frame. If you cut the plastic tube end off that has the ridge, it will not hang up on anything and it will just slide out.
The vapor canister bracket has a clip that you depress and then the canister can slide off the bracket. Loosen the two allen head bolts that hold the bracket on to the frame, remove top bolt then rotate bracket and put the bolt back in and tighten it down, then remove lower bolt and bracket, reinstall lower bolt and tighten it down.
The single hose on the right side of the bike from the vapor canister goes up under the tank and doesn't connect to anything it is just a breather hose you can just pull it out.
On the left side of the bike you have two hose's coming off of the canister. The canister is labeled carb / tank, disconnect the tank hose and follow it up the frame to a little vapor valve, remove hose from the bottom of this little vapor valve and remove the hose. This is now your 49 state tank vent, you can also get the 49 state vent hose that connects to the vapor valve and runs up under the tank, it is in the Harley parts catalog (99439-06A) item 13 on page 90 P/N 27296-04A TUBE, VALVE TO ATMOSPHERE and a retaining clip item 7 P/N 10113 CLIP, DOUBLE HOSE.
Disconnect the carb hose from the vapor canister, this line goes up the frame and under the tank to a connection behind the top left side of the air cleaner, it connects to the intake manifold, disconnect and put a cap on the port of the intake. (In the Harley parts catalog (99439-06A) on page 20 they list a cap plug item 21 P/N 90383-98 CAP PLUG, INDUCTION MODULE that might be the one to use.) This hose is difficult to remove, I took off the rubber hose from the plastic tube by the intake and pulled the hose out from the front of the tank and broke off a clip that supports a harness that comes out of the bottom of the tank, but I was able to ty-wrap that harness to another harness under the tank near the frame. If you cut the plastic tube end off that has the ridge, it will not hang up on anything and it will just slide out.
The vapor canister bracket has a clip that you depress and then the canister can slide off the bracket. Loosen the two allen head bolts that hold the bracket on to the frame, remove top bolt then rotate bracket and put the bolt back in and tighten it down, then remove lower bolt and bracket, reinstall lower bolt and tighten it down.
Thread Starter
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Intermediate
Joined: Feb 2009
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From: Northern California
Originally Posted by WS6 Formula
Removing the vapor canister:
On the left side of the bike you have two hose's coming off of the canister. The canister is labeled carb / tank, disconnect the tank hose and follow it up the frame to a little vapor valve, remove hose from the bottom of this little vapor valve and remove the hose. This is now your 49 state tank vent, you can also
Removing the vapor canister:
On the left side of the bike you have two hose's coming off of the canister. The canister is labeled carb / tank, disconnect the tank hose and follow it up the frame to a little vapor valve, remove hose from the bottom of this little vapor valve and remove the hose. This is now your 49 state tank vent, you can also
Is it safe to assume the little vapor valve you refer to is a one way valve allowing air into the gas tank but not out? Also, is this vapor valve "position sensitive"? Currently it's exposed to view and strapped in a vertical position and I'd like to move it out of sight to under the gas tank in a horizontal position.
I'm still curious to know exactly what this system is supposed to do and how it's supposed to do it. Any feedback or links to additional information is appreciated.
Thanks, Terry
Road Master
Joined: Feb 2010
Posts: 1,210
Likes: 1
From: LI, NY
Gas vapors leaving the tank is a form of pollution So the caps are now non vented.
Vapor canister system on cars allows air to enter the fuel tank so air pressure in tank is kept the same as outside the tank. Other wise fuel won't flow out of the tank. It does what the old vented gas caps did.
Being the VC system allows air to enter the tank gas vapors can leave the tank to the amosphere when the engine is not running by the same path it lets air in. So all air leaving or entering the system flows through the charcol filled canister.
When the engine is off the gas and air vapor that leaves the tank has to flow through the canister where the charcol traps the gas vapor.
When the engine runs, manifold vacum is used to pull fresh air through the canister where this fresh air absorbs the gas vapor into the intake to burn in the engine.
Vapor canister system on cars allows air to enter the fuel tank so air pressure in tank is kept the same as outside the tank. Other wise fuel won't flow out of the tank. It does what the old vented gas caps did.
Being the VC system allows air to enter the tank gas vapors can leave the tank to the amosphere when the engine is not running by the same path it lets air in. So all air leaving or entering the system flows through the charcol filled canister.
When the engine is off the gas and air vapor that leaves the tank has to flow through the canister where the charcol traps the gas vapor.
When the engine runs, manifold vacum is used to pull fresh air through the canister where this fresh air absorbs the gas vapor into the intake to burn in the engine.
Outstanding HDF Member
Joined: Nov 2009
Posts: 2,960
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From: Sonoma County, CA
I removed my canister shortly after getting my 2010 Fat Bob. I did leave the valve in place on the side of the neck in front of the tank. I haven't had any issues with the bike (that I know of) except I'm adding more pollutants to the air instead of into the charcoal canister. No pressure builds up in the tank and blows out when taking off the gas gap.
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Intermediate
Joined: Feb 2009
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From: Northern California
So it seems the vapor volume in the gas tank has to both expand and contract at different times and for different reasons. (lose of gas and temp/altitude change) If that's so, then it seems the vapor valve must be a two-way valve, and probably pressure activated. Please correct me if I'm wrong.
I still want to shorten the hose to that valve and move it out of sight under the gas tank. Someone let me know if there is a good reason not to, Thanks.
I still want to shorten the hose to that valve and move it out of sight under the gas tank. Someone let me know if there is a good reason not to, Thanks.
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Road Master
Joined: Nov 2010
Posts: 1,115
Likes: 69
From: Bay Area, NorCal
Vapor valve....
Somewhere in the owner or service manual I read the vapor valve also serves as a stopper to prevent fuel leakage in the event of a tipover. If so, placement in horizontal or vertical position might be critical to its function. Might have to check with the service dep't for verification. I just left mine where it was originally installed as I don't consider it too much of an eyesore. Peace.
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Or what WS6 wrote.I just bought the 49 state tube that runs from the valve, under the tank and down by the rear motor mount. Finally did it when I relocated my ignition switch to the console on my SB. Already had the double line clip.
90383-98
CAP PLUG, INDUCTION
27296-04A
TUBE, VALVE TO ATMOSPHERE
CB
P.S.I also saved everything so in case I have to put it back on.