Author Topic: Gas runoff? (Read 4969 times)

dizanott · « **on:** April 18, 2005, 09:34:10 PM »

Hey all, i'm a first time bike rider and owner. I just bought my 2001 bandit 600s. I noticed a couple of spots on the ground below my bike after riding it for awhile. It smelled like gas when i touched it. This only happened after i filled the tank to the top for the first time. the spot on the ground is right in front of the rear wheel. I noticed 2 hoses coming down that aren't attached to anything. it appears that this is what the gas (if it is indeed gas) is coming from. are these supposed to be attached to something? is this normal? i'm a first timer, so if this is natural i'd really like the reassurance. hope this post makes sense, if i need to explain it better just ask me. other than this minor thing that i'm unsure is even a problem, i am proud to be a new bandit owner!

PeteSC · « **Reply #1 on:** April 18, 2005, 09:49:16 PM »

One hose should be the drain hose from the airbox. On a B12, there's a removeable cap on it.)
The other, is a drain hose that is hooked to a drain pipe that passes THROUGH the tank, and is only supposed to drain WATER that collects around the recessed gas filler cap on top of the gas tank. (Rain water, wash water, etc.)
If gas is leaking out of this hose, you've got problems. Possibly a cracked 'pipe' in the tank, or a some serious rust inside the tank.

Make sure the drippage is gas.

dizanott · « **Reply #2 on:** April 18, 2005, 10:00:04 PM »

being a newbie, i guess i'll take it to my local dealership. it only started happening after i filled the tank, and i filled it really full, and as i've rode the last couple of days it has become significantly less. also it only happens when it is realllllly hot outside. correct me if i'm this is stupid, but here is my theory: the heat of the atmosphere is making the gas expand and the vapors are rising and going out that water runoff thing. and as i use more gas, it doesn't do this as much because the gas isn't expanding high enough to go out of the tube. does this sound like a reasonable guess? (also, it only does this during the day, at night (when it is cool outside) there isn't any "leakage" at all)

PaulVS · « **Reply #3 on:** April 18, 2005, 10:09:18 PM »

Quote from: "PeteSC"

One hose should be the drain hose from the airbox. On a B12, there's a removeable cap on it.)
The other, is a drain hose that is hooked to a drain pipe that passes THROUGH the tank, and is only supposed to drain WATER that collects around the recessed gas filler cap on top of the gas tank. (Rain water, wash water, etc.)
If gas is leaking out of this hose, you've got problems. Possibly a cracked 'pipe' in the tank, or a some serious rust inside the tank.

Make sure the drippage is gas.

Not to thread steal here... but wow... fortunate timing for me, Pete. I just put my rejetted carbs in the bike, replaced the gas tank and after taking it for a test drive, I washed the bike. I noticed, for the first time, that when I rode it after washing it that water was trickling down the gas tank from the filler cap area. Maybe I didn't reconnect a drain hose correctly? Which hose is the drain hose for the gas filler cap???

EDIT:

OOPS... nevermind. I found it. It's the larger of the 2 hoses. I just found out I had crimped mine while buttoning the bike back up and about a 1/4 cup of water just drained out of it. Thanks Pete!

Airmotive · « **Reply #4 on:** April 18, 2005, 10:12:29 PM »

Regarding the fuel issues after filling the tank on a hot day.... Your logic is very sound. Happens on light airplanes all the time; no reason for it not to happen on a bike as well.

dizanott · « **Reply #5 on:** April 18, 2005, 11:15:38 PM »

that info makes me rest a little easier. i'll probably get it checked out one of these weekends just to be safe. The bike looks like it's been taken very good care of. only 2 other things i need to look into on it right now, but i'll put those in other posts.

aussiebandit · « **Reply #6 on:** April 19, 2005, 08:44:31 AM »

Try not filling you tank so much on those hot days unless you're going to ride some distance. My B12 does the same thing when the tank is full and the temp over 28c.

land_shark · « **Reply #7 on:** April 21, 2005, 11:14:13 AM »

Quote from: "PaulVS"

Quote from: "PeteSC"
One hose should be the drain hose from the airbox. On a B12, there's a removeable cap on it.)
The other, is a drain hose that is hooked to a drain pipe that passes THROUGH the tank, and is only supposed to drain WATER that collects around the recessed gas filler cap on top of the gas tank. (Rain water, wash water, etc.)
If gas is leaking out of this hose, you've got problems. Possibly a cracked 'pipe' in the tank, or a some serious rust inside the tank.

Make sure the drippage is gas.

Not to thread steal here... but wow... fortunate timing for me, Pete. I just put my rejetted carbs in the bike, replaced the gas tank and after taking it for a test drive, I washed the bike. I noticed, for the first time, that when I rode it after washing it that water was trickling down the gas tank from the filler cap area. Maybe I didn't reconnect a drain hose correctly? Which hose is the drain hose for the gas filler cap???

EDIT:

OOPS... nevermind. I found it. It's the larger of the 2 hoses. I just found out I had crimped mine while buttoning the bike back up and about a 1/4 cup of water just drained out of it. Thanks Pete!

Careful with that crimped hose! I posted a thread here about what can happen, and how I hopefully fixed it. Basically, it filled with water, froze, and burst the drain pipe inside the tank. So, I was constantly leaking fresh gas. HTH!

tacoman · « **Reply #8 on:** April 21, 2005, 02:45:57 PM »

You have probably witnessed gas expansion. The gas pumps from a cool underground tank and you put it in your warm bike tank (sun on top, hot motor from below). The expanding fuel has to go somewhere.

terrebandit · « **Reply #9 on:** April 21, 2005, 10:14:01 PM »

If you overfill at a gas station and a splash or two of gas goes obove the neck of the filler cap, it will leak out that hose. No worries dude.

Dave