2004 V11 Cafe Sport Fuel Tank Leaking

[geddo]

Please forgive my inability to describe this issue in a more technical manner.

 

A couple years into owning my 2004 Cafe Sport gas leaks appeared from one of the hoses below the bike just in front of the back tire. This would happen on hot days and anytime it was parked in the sun, the leak was small. The gas tank was also depressurized to the point that when I opened the fuel cap a rush of air would suck into the tank and fill it back out. The leak had become more regular over the years but I could still work around it by opening the fuel cap allowing air in. I had a local shop look at it but they had no idea what was wrong and couldn't reproduce... always the case.

 

A few months ago I took the bike in to fix another issue and I had them look at the fuel issue again, this time they said that sometimes the lines are not connected properly and they would look at it but more likely the lines inside the tank have failed and I would need a new tank which they would request via warranty replacement.

 

After the bike was repaired I drove it home and of course it started leaking again, only this time it is not leaking from the hose under the center of the bike but instead from an outlet under the clutch side of the tank just above the cyclinder! And if that wasn't bad enough it leaked non-stop for 3 days, opening the cap and reclosing no longer worked to stop it. I now have to leave the cap open all the time, not great for the bike of course but better for my house's aversion to fire.

 

So I call them back and after repeated attempts to get a hold of someone I am told that it may not be covered under warranty since it was only covered for 6 years and a new tank will likely cost $1,200 - $1,500... ouch!

 

So I thought I would post here to see if any of you had similar problems and if there is a cheaper way to fix this problem, its pretty useless as is. Are there replacement parts I can put on the tank or workarounds. Anything else I could check or try to fix it or should I just look for a used tank?

 

Thanks,

Geddo

[gstallons]

Hmmmm, where do you live ? You need to find a friend that knows something about finding fluid leaks. Does your bike have an external or internal pump? If your tank has a black rubber pad on the top of the tank it has an external pump. If it is the other (internal pump), you have a problem with the mounting of the pump to tank or a fuel line connection or connector problem.

KEEP US posted.

[geddo]

Hmmmm, where do you live ? You need to find a friend that knows something about finding fluid leaks. Does your bike have an external or internal pump? If your tank has a black rubber pad on the top of the tank it has an external pump. If it is the other (internal pump), you have a problem with the mounting of the pump to tank or a fuel line connection or connector problem.

KEEP US posted.

 

I live in San Jose Ca., no pad on top of tank

 

The leak is now happening from the black nipple just above the bright red wire shown here (or just to the left of the silver nut):

 

Internal pump issue doesn't sound good, is that fixable if it is the issue?

[docc]

Hmm, that appears to be the airbox drain. The bright red wire is the spark plug wire and the two should not be allowed out on a date by themselves!

 

The center hose leaking before indicates the tank was not venting normally. I wonder: what did the shop change? Did they actually change the tank? Or did they reroute or plug off the vent lines?

 

Normally, that airbox drain only captures incoming moisture. In order for it to be dropping fuel, raw fuel must be kicking back into the airbox.

[geddo]

Okay so I fired it up for 1 minute, shut it off and waited an hour or so and the leak started again. I did some more digging and the leak is actually above that tube, it just appears to be coming from it as it drips down. There is a metal outlet in the tank about 5 inches above this airbox hose and that is where the leak is coming from, I have some video of it I will post tomorrow.

[rossi46]

There is a metal outlet in the tank about 5 inches above this airbox hose and that is where the leak is coming from, I have some video of it I will post tomorrow.

are you talking about the 2 nipple type outlets? one (i think) is a breather the other will drip fuel if its overfilled, there should be 2 black hoses attached-if theres some 'plumbing' issue and the tank is pressurised maybe fuel is seeping out here?

[geddo]

Hey Rossi, way to take out Stoner LOL

 

I think you are correct, here are the images:

 

 

 

She's a bit incontinent

 

and the video, skip to 20 seconds in... its hard to hold a flashlight and shoot video with a phone:

[grossohc]

i only have one black hose to connect to the tank (right side) for the overflow, wasnt the other hose for the tip over mechanism/charcoal cannister that is fitted to US bikes!!, maybe that gubbins should be junked.

[rossi46]

I only had one hose aswell.I put another on just in case the parts diagram seems unclear, I guess the right side is the most important,geddo what does the regulator look like? is that blocked ? could that be the issue?

[geddo]

I only had one hose aswell.I put another on just in case the parts diagram seems unclear, I guess the right side is the most important,geddo what does the regulator look like? is that blocked ? could that be the issue?

 

Not familiar with that, how would I check that?

[rossi46]

its directly opposite the fuel tap on the right hand side of tank

[geddo]

Looks like it is internal to the tank on my '04.

 

http://www.v11lemans.com/forums/index.php?showtopic=13245

[rossi46]

ah well spotted, tank off time I guess!

[v11cafe]

Looks like it is internal to the tank on my '04.

 

http://www.v11lemans.com/forums/index.php?showtopic=13245

 

yes, pump is internal

but as for the leak never happened to me

one breather hose is connected

 

perhaps you can warm up the engine with the fuel cap open and then let it cool for some time

if it leaks again it won't have to do with tank pressure

[HaydnR]

 

 

 

 

 

I would guess that your breather pipe (connects at 'e' in top photo) is blocked either inside the tank or the hose is blocked or kinked. If your fuel vapour system ( I take it is a US bike) was connected as it should have been to point f (the part that is now leaking) and the breather was blocked this would have caused the vacuum inside the tank as the vapour system uses the vacuum points on the inlet manifolds to suck vapours from the tank.

It now seems that the shop has disconnected the vapour system so the suction has stopped but with the breather blocked the tank is pressurising which is causing the leak that you now have.Maybe.