gas smell from vent hose

I smelled gas from my bike (cbr 600rr - 05) and took it into the
dealer for inspection. They confirmed that the gas I smelled is coming
from my vent hose. The service guy said that it's due to the fuel
vapors and completely ok. But no matter how much gas is in the tank, I
smell the gas vapors from the overflow hose. Further, some guey residue
that smells like gas is building up (it is gas)at the end of the
overflow hose. Is that normal? i put a flash light to the end of the
hose, and I actually see the vapors. There are a couple of drops of
gasoline that dripped from the vent hose too. is there a way to prevent
so much vapor coming out?? The bike runs fine though and only vents
stronger gas smells after long rides. Is that normal? bike has a
little over 1,100 miles.

 

Do you have to disconnect this hose from something to see the vapors
and the gasoline dripping? My GSXR has a vent hose coming from the top
of the gas tank and that hose just vents straight to the atmosphere.

Smelling gasoline fumes is normal under certain circumstances, but
seeing a lot of gasoline dripping out of hoses is not normal.

Gasoline and water are both liquids. They both have a temperature where
they bubble
and boil when heat is applied. They both have a lower temperature at
which they evaporate. If the temperature drops below the evaporating
temperature, the fluids condense.

So you are smelling and seeing gasoline which has evaporated or
condensed.

Your machine probably has an evaporative control system. Gasoline in
the tank evaporates and the fumes are stored in the charcoal canister
until you start the engine. Then they are sucked through a one-way
anti-backfire valve into the intake tract of your engine.

A very small amount of air is normally sucked through the bottom of the
canister when the engine is running.

If you over fill the gas tank above the filler neck that sticks down
into the tank about two inches, you'll get liquid gasoline down in the
charcoal canister and it may drip out the bottom.

If you overfill your gas tank and park in the hot sun, the gasoline in
the tank will expand, and that could cause liquid gasoline to flow into
the evaporative control system. You would smell a strong odor of
gasoline evaporating. If you see gasoline dripping underneath the
canister, you've overfilled the tank and have flooded the canister.

There is probably a water separator tube going to the gas tank too. The
water that is separated probably goes through a hose that dumps the
water onto the road behind the engine.

All of these parts are included in your warranty. Honda probably has to
warranty the emissions control system for 50,000 kilometers. The exact
distance will be right in the front of your owner's manual. If you
believe that your evaporative emission control system is not working
right, you have the right to return the vehicle to the Honda dealer for
warranty repairs.

 

Gas expands and contracts plus is volatile.

The vent is there for a reason which is to VENT to the outside. That
means both suck and blow. You smell the blow stages. Many new bikes come
with charcoal cannisters to adsorb these odors. It's part of life.

 

my bike doesn't have a charcoal cannister.. the bike is in texas.. only
california bikes have this... so this is still normal?

 

Yes and many non-CA bikes have this as some mfgs don't wish to make two
versions of their bikes. For example, my non CA KTM has a cannister
(well, it did).

 

are you sure its the tank vent and not a carb overflow/drain hose????

 

I'm positive.. it's the vent hose.. from what others have told me, the
vent hose will blow out and suck in air to control the pressure inside
the tank.. gas vapor will come out.. they said that it's normal. the
bike is a non-california bike so the charcoal canister is
non-existance.. thus, i'll be able to smell the gas vapor.. i guess,
it's not really common, but it's normal.. most of the time, you are
riding so you won't be able to smell it, but if you have it idling
after a long ride, you will notice it.. anyways, that's just what i
gather from posting this on other forums..