Fuel Leak Help

[georryan]

Heya, I'm new to the forum and I have a weird issue maybe someone has seen before.

 

I have an 02 r1150rtp, I started up the bike today after it had been sitting on the sidestand for a few days of no use. The gas tank was over half full, maybe more, and when I started it I sat there for a little bit then smelled gas. I had a puddle under me. After inspecting it, it looked like the leak stopped when the engine was cut, and it didn't look like it was coming from the quick disconnects. It was enough fuel to come down from different spots along the right side of the bike and flowed over the drain and fill plugs of the tranny.

 

After a few starts and stops to see if I could locate the issue, it stopped. I let the fuel evaperate, came back and started her up and it was fine. No leaking anywhere that I could see. I drove it to work and back and no problems whatsoever.

 

I've had this happen one other time on me. I had thought I had a leaking line so I didn't ride it. I came back that evening started it up and couldn't find a leak. I thought it might be a fluke, but now after a second time I'm going to pull the sides off this weekend and see what I can find.

 

It definately seems to leak a lot while the engine is running. Once it's stops, the leak stops. It almost seems like it has to be a part that has a seal in it that gets seated after the bike warms up or something. Are there more than one set of quick disconnect fuel lines, or are the only ones just above the right cylinder head?

 

Any suggestions as to what I should be looking for?

 

-Ryan

[T__]

Ryan, difficult to tell what you have there..

 

A couple of things it could be:

 

You say the tank was overfull? If it was & the fuel heated & expanded it could have been forced out the tank vent.. The tank vent comes out just above & behind the R/H foot peg..

 

Or, you might have a leaking fuel pressure regulator.. That regulator sits just in front of the air box up above the trans.. Mighty difficult to see it in there & even more difficult to replace it if that is your problem.. Hope this isn’t you problem as it is real PAIN to replace..

 

Maybe locate the tank vent (one of the hoses that exit just behind the R/H foot peg) then next time you have the leakage problem look closely at he vent line for the fuel coming out there..

 

 

Twisty

 

[Ken H.]

Yes, the key to this is going to be figuring out if the leak is before, at, or after the pressure regulator. It’s just going to take a lot of looking.

[GordonB]

One place to look is where the fuel lines connect to the fuel pump assembly just outside the tank. You can see this by looking between the front forks from the front of the bike with a flashlight. I had a similar problem with my 1100RT. The fuel line clamps loosened with age and as the fuel made its way past the loose fittings it swelled the rubber and tightened back up.

[Jerry Duke]

My money is on the fuel rails. Exact same conditions for me and it was the metal lines near the regulator. Major pain. Tank and battery box and ABS unit have to come off to replace them.

[georryan]

Thanks for the input guys, it gives me a good head start on where to be looking.

[knight88]

My money is on the fuel rails. Exact same conditions for me and it was the metal lines near the regulator. Major pain. Tank and battery box and ABS unit have to come off to replace them.

 

inquired at one time about replacing the regulator at an independent BMW bike shop and the mech told me he could change it out by putting a hole in the bottom of the battery box to get to it, and not have to remove too much stuff. Don't know how feasible it is but maybe something to look at the next time it needs to be changed.

[georryan]

So as an update...

 

I took the bike down to A&S Bmw here in Sacramento, and they were having a tech day. They do this once a year and have people bring in their bikes and let them use their lifts to work on their bikes. The techs go around from bike to bike giving suggestions answering questions and educting people on how to work on their bikes.

 

I talked to a tech and he said the problem was the two rubber hoses on the end of the quick disconnects. He said that the metal clamps on them are often not tight enough and when the bike is cold they'll leak a bit. He suggested I use a cv joint clamping tool and tighten the clamps.

 

He then said to bring the bike in and he'd show me how. I didn't have my tools so he offered me his. I had it in in a few minutes and sure enough, that's where it looked like the leak was coming from.

 

So now I probably have it all fixed. Time will tell, but the guys down there at A&S were top notch, friendly, and very helpful.

[lvnvbiker]

Good deal, and cool shop too. I've been meaning to talk to the guys at Vegas to see if some such thing is possible, but have not had the chance yet. When BMW's were sold at Yankee Trader here the guys used to be realy helpfull, and had no problem showing me stuff when I would go visit and buy parts fpr my HD.

[Ken H.]

inquired at one time about replacing the regulator at an independent BMW bike shop and the mech told me he could change it out by putting a hole in the bottom of the battery box to get to it, and not have to remove too much stuff. Don't know how feasible it is but maybe something to look at the next time it needs to be changed.

I can’t imagine. The regulator sits between the battery box and the air box. And is clipped to the air box. I can’t fathom a way to get to it from the battery box. Hole in the bottom aside.

 

I suppose there’s some theory that if you cut out the front of the air box you could get to it, but then you’d have a messed up air box.

 

[Jerry Duke]

I looked at it and the repair manual for over an hour before I finally decided the repair manual steps were the only way. But my bike is an R11S so other bikes might be different.

[DavidEBSmith]

inquired at one time about replacing the regulator at an independent BMW bike shop and the mech told me he could change it out by putting a hole in the bottom of the battery box to get to it, and not have to remove too much stuff. Don't know how feasible it is but maybe something to look at the next time it needs to be changed.

I can’t imagine. The regulator sits between the battery box and the air box. And is clipped to the air box. I can’t fathom a way to get to it from the battery box. Hole in the bottom aside.

 

I suppose there’s some theory that if you cut out the front of the air box you could get to it, but then you’d have a messed up air box.

 

Well, you might be able to get to the regulator, but you can't remove the fuel distributor assembly through the battery box. At least not on an R1100RT. The hard plastic lines on the fuel distributor run between the bottom of the subframe and the top of the airbox and you can't get the whole assembly out without lifting the subframe. If it was just the regulator itself that was bad, maybe you could get to that through the battery box and maybe you could remove it from the distributor assembly without taking the assembly out.

 

But I think I've only heard of a regulator going bad once. If there's a fuel leak in this area, usually it's one of the plastic lines on the distributor cracking.

 

Illustration here: the regulator (2) vs the distributor (1).