Hello All,
I'm fairly new to the forum and also new to Harleys, not new to riding as I've been riding for about 40 years. Several months ago I purchased my first low mileage Harley (Super Glide Custom) and its been a blast, I love this thing. I've taken it on a couple of long distance trips to the mountains of NC & TN, across the state of Florida a couple of times, and I get it. The unique visceral feeling that you experience with a Harley is unlike any other brand that I've owned. Yeah I know, why did I wait so long? It's kind of a long story but to simplify it, I've always likes sport tourers, European roadsters and the likes, also my previous riding style simply wasn't cruising.

I have four bikes and a couple of years ago my garage hit capacity, so I built a room addition on the back of the house so that I had a place to store three of my bikes and gear all in one place. The three that I prefer to keep in the room are a Moto Guzzi Griso 1200, A Kawasaki and the FXDC. The issue that I'm having is that the Super Glide's tank is venting fumes to the point that if I keep it in the room, I fear an explosion, the fumes are that strong. Its a small room, 10 x 14 with a 6' wide double steel door setup to access the bikes in and out of the room. There's also an 8' double sliding glass door leading from the house to the room so no fumes enters the house at all. I've never had this problem with any of the other bikes that I've kept in the room. I always let the bikes cool off before storing them in the room because I know when their hot, they all will vent fumes.

The only solution that I've come up with was to keep the FXDC in the shed out back which has two vents and a screened window, or to install some type of vent system in the room which I'd like to avoid because its climate controlled with the house system. My only issue with keeping it in the shed is Florida's high humidity and rust and corrosion issues. So I wanted to put it out here to see if anyone knows of a possible solution so that I can get it back in the room. I know all bikes have to vent, but this one is like having a 5 gallon bucket of gas in the room with no lid on it. I don't have this issue with any other bike, is this normal for Harleys, or is this excessive venting, is there possibly something wrong with the tank vent system, it does work extremely well, too well. I appreciate any ideas or input you all might have.

 

I've never noticed fumes from the tank venting in my garage. You may have a leaking console gasket or somewhere else in the fuel delivery system.

 

As mentioned, sounds like your FXDC is losing fuel somewhere. Most obvious spots to check would be the fuel fitting and hose under the rear of the tank, as well as the crossover hose under the front of the tank. You might also check for a loose/cracked vent hose under the console at the top of the tank. Hope you figure it out....
~

 

 

It could be the console, I'll check there next. I've already checked all the hoses and fittings underneath the tank and they're good.
Thanks,

 

I'd think you need to look for a fuel leak, not a vapor leak. There's no reason Harley gas should evaporate at a higher rate than any other brand, unless all your other bikes are California bikes with vapor collection systems.

 

3-4 drops of gas can smell up a garage. Be sure the top forward facing vent hose is secure on hose barb. Make sure it is in good condition back to the vertical restricter on the end. That restricter is important. It keep fwd surge of raw fuel from coming into hose. Tank vents in only at the cap. Vents out when under pressure out vent hose. Air only. Not raw fuel.

 

I would NOT have anything with gas fumes issues near my house or in a closed environment. Not normal for any gas engine now days.

Opened my shop once and caught a whiff of gas. Kept it opened till I found that a mower with fuel pump didn't shut off and leaked fuel into the engine when not running. Probably result of ethanol gas. On/off value fix that. All my lawn equipment has that kind of valve now.
hth

 

Faulty gas cap can also cause this.

 

I've checked the gas cap and replaced the O-ring a couple of weeks ago because it had a little nick in it that I thought might be the problem. I've also checked for leaks on the supply line and connections and the crossover line and clamps, no sign of leakage there. I haven't had time to pull the console yet. I'm starting to wonder if I might have a faulty vapor vent valve that's either cracked or stuck open, allowing it to continuously vent vapors. My usual routine after a ride is that I head straight home and park it with a partial tank, and I don't fill it back up until the next ride. This leaves plenty of room in the tank for vapor build up. I recently stopped and filled it up on the way home a couple of times and I've parked it inside the shed with a full tank, both times I had no fuel vapor issues. After sitting with a full tank for the last two days, no vapors. Until I get it figured out, I'll just have to make sure its filled up on the way home.