Gliden it's not your air filter getting gas on it, your fuel injectors spray high pressure fuel directly down onto the intake valves when they are open, and they don't leak fuel when they aren't operating. There's no way gas can get way past the closed throttle body to the air cleaner.
If you go sniffing in front of your rear tire where your tank vent is I think you'll find the source of the raw gas smell.
Gliden it's not your air filter getting gas on it, your fuel injectors spray high pressure fuel directly down onto the intake valves when they are open, and they don't leak fuel when they aren't operating. There's no way gas can get way past the closed throttle body to the air cleaner.
If you go sniffing in front of your rear tire where your tank vent is I think you'll find the source of the raw gas smell.
Ok gotcha. I always thought it was my teardrop ....thanks Joe...
Joe I'm thinking you could be a candidate to go on Shark Tank if you figure this out
$$$$$$$$
LOL Thanks Gliden.... but this problem was figured out a LONG time ago. I'm pretty certain it was 1968 when evaporative emission controls (aka EVAP system) became a federal requirement (along with a positive crankcase ventilation system, side marker lights and other things). Every car built since then has the fuel tank vent into a charcoal canister, and the canister needs a vacuum from the intake so that the HC can be removed from the canister and burned. It's a simple system that keeps the car from emitting raw gas fumes (Hydrocarbons) when the tanks breathe.
It's a controlled and computer monitored system in cars, that's why you get a check engine light if you leave your gas cap off, the car would vent fumes like that and it's a no no. I'm just amazed that a brand new Harley doesn't have this simple and effective emission control!
There are literally hundreds of threads on this, I'm surprised the nobody has thought to install the actual solution in any of the threads. On the contrary, there are plenty of threads on how to remove the EVAP system as "it's ugly". It doesn't hurt performance at all, just adds a lb or two to the bike (and I can't complain about a couple of lbs when I could stand to lose 20 myself ).
I'm very happy a Springer brother has donated his unused canister to me. I'll be sure and post up my install pics and the effectiveness of the system in case anyone else wants to solve this problem of the raw gas smell after a ride.
Until then, it seems blowing a fan on the bike prevents the heat from the engine from heating up the tank enough to cause it to vent the HC fumes.
I tell you what, Joe; I don't want to be near my horses fermentative vent when they are emitting raw gas either.
No federal regulation on that (yet) and it contains hydrocarbons.
Be warned Bone Doc... the white house has agricultural methane emissions in its cross hairs for regulation... You might soon be forced to lace those equine water troughs with GasX to reduce their flatulence!
I'm pretty certain it was 1968 when evaporative emission controls (aka EVAP system) became a federal requirement
Maybe in cali...normal cars didn't get that crap till 71
I think that check valve on the end of your vent tube is holding pressure on the tank till it gets to a certain pressure...then it blows at once..giving you the strong smell...my bike never smells like that...even closed up in a toyhauler...or in the winter when I park it in the house.
I actually pulled the check valve off, you can blow through it no restriction when it's upright, if you tip it over it stops the flow so gas won't leak out. You can't suck air through it at all. It's not an inbound vent for the gas tank. The gas cap allows air into the tank but no fumes to get out. I tested my cap as well for proper operation. Cap lets air in, check valve lets it out. Fumes only come out of the tank after a long ride in my experience, the engine heats up the tank and the vapors flow out through the check valve. It stops as the bike cools and a fan on the engine will prevent the heating of the tank which causes this. When the bike is cooled off it has no smell at all. It only smells for about a half hour after a ride.
looking at this pic the solenoid #4 is plumbed into a vac line to the intake. the computer periodically operates the solenoid to open and allow the eng vac to pull the built up gasses in the charcoal canister into the engine/intake and be burned . it is only sealed this way due to CA emissions requiring NO raw HC, hydrocarbons be released into the atmosphere. all cars evaporative systems operate in a similar matter with the exception of pressure sensors and shut valves for testing purposes. . Line 5 comes from the intake, line 6 to the canister. since you're not trying to comply with CA emissions, you won't need any of this.
note that line 6 goes into the outer most port of the canister, the side where the mounting tabs are molded into the canister. leave this open. run your vent from tank to the inner port where line 3 attaches and the fumes will go through the canister and then vent into the atmosphere after it has passed through the charcoal and should effectively eliminate the fumes to the point of not being able to detect it.
early cars fuel tank and carb bowl vents were plumbed into a basic canister with the bottom of the canister perforated/slotted to allow the treated fumes directly into the air.
FFB thanks for your post! I didn't realize that the original canisters were open to air.
The service manual page for my 2003 canister is below. As you can see, it is a simpler system. Only the tank vent and the vacuum from the throttle body hook to the canister. I can't tell if that elbow on the back is a cap or not. On the carb bikes that port goes to the air cleaner. My factory air cleaner doesn't have a port on it.
On my bike the throttle body port is on the air cleaner side of the throttle blade so it doesn't have constant vacuum, only partial vacuum when the throttle blade is open. Thus the canister gets the cleaning vacuum only during part throttle cruising, not at idle.
The question is would this canister work and for how long if I didn't run the vacuum line to the throttle body. Since it's pretty easy to raise the tank and run the line I'll probably do it the right way.
01-02-2016 | 08:19 AM
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