100 miles on my new break out. Brother in-law came down on his bike. While waiting for him to show up, I pull the BO out of the garage. It was 95 degrees when I did that. The BO sat in my driveway for 45 minutes.

When he got to my house, I walked out and saw a puddle under my bike. WTF??? Smelled like gasoline but was clear.

Found the fluid was coming from a vent tube. I still rode the bike around town. Since this is a vent tube, is it meant for fluid to be vented?

Vent tube is on the left side and hangs over the belt.




What is it venting? Did the temperature outside cause the fluids to come out? Do I need to make a trip to the dealer? Or is this all normal and I just need to chill out??

 

chill out. Look at the front of your tank, there should be a hose on the front (near the top), that hose should run down the backbone of your bike and drain there. it's the fuel overflow/overfill vent hose. no big deal.

 

Thanks Jim. So even with 1/4 tank left, it would be venting fuel?

 

No, it shouldn't. It should only vent liquid if you overfill your tank and then let it sit in the sun, which is what happened to me one day. It's a pop-off overpressure vent, and it should vent from the top of the tank.

I made the mistake of unscrewing my flush-mount gas cap with the tank filled to the top, and the bike got a gas bath!

 

The primary purpose of the fuel tank vent and hose is so fuel can pulled from the tank. If the tank weren't vented it would starve for fuel. I've seen motorcycle fuel tanks dimple in from the suction when a vent hose was blocked.

The secondary purpose is so fuel and vapors can escape from the tank, either when overfilled or when the fuel vapors expand due to heat. On cars, these vents go to a charcoal canister usually mounted below the fuel tank. Topping off the tank usually results in pushing fuel down the vapor/overflow tube and into the canister making it worthless. Some motorcycles sold in California have these canisters as well.

On a 49 State bike the only downside is raw fuel can eat away at powder coat and stain aluminum. One sure way to know if your vent tube is blocked is if the bike starves for fuel and/or stops running and you remove the fuel cap followed by a whoosh of air sound.

 

Bike isn't starving for fuel, so who knows why it's doing this.

What is the white stuff at the end of the hose?

 

Isn't that the battery vent?

 

These batteries are not vented.

 

ever figure this out?
my 05 did this today for the first time, its not hot, only about 50 degrees, its about 3/4 full.

 

That's the fuel vapor relief hose. I did a lot of work on this as my bike was smelling like gas after a ride in my garage and I traced it here, the hot engine was heating the gas in the tank and it was venting off the fumes. I got a California only charcoal canister and installed it, no more gas smell when i quit riding.

The tank vents from the fuel cap - if you take it off, you can suck air through it but it's one way, you can't blow through it. The vent line you see here has a valve in it that prevents air from going in and if the bike tips it prevents anything (like raw fuel) from coming out.

Here is my research and part numbers if you want to get rid of the gas smell.

https://www.hdforums.com/forum/softa...tank-vent.html