Trying to Locate Fuel Leak

[JohnNorCal]

I have a 2002 1150RT.  About a month ago I started it up and got about a mile before I smelled gas.  There was gasoline dripping down on the left side of the bike onto the catalytic converter.  Rode it  home and parked it for a few minutes.  Started it up again and the fuel leak started again.  I live in N. Idaho and decided that I would wait until the snow fell before digging into it.  (three snow storms later....)Today I stripped off the tupperware and started it up.  No fuel leak.  Let it get warm.  No fuel leak.  I can see on the rear of the starter where the fuel had dripped down across the road grime.  The only fuel line on the left side of the engine is the one feeding the injector.  Looking at the Chilton's manual it looks like that line comes from the fuel pressure regulator. 

 

I am thinking that it has to be an o ring as opposed to a fuel line because it is intermittent and it never leaks when parked.  I see in the Chilton's illustration that there are two o rings in the fuel pressure housing.  I can't really see if the fuel line has a clamp on it where it joins the fuel pressure regulator.  I at first thought that the fuel line was metal but it looks to be a plastic of some kind but again, since it is not leaking today I doubt that the line is cracked.  Chilton's says that you have to remove the transmission in order to get to the fuel pressure regulator.  That is way beyond my capability if that is true.

 

Full disclosure, I did replace the plastic factory tank disconnects a few years back with metal ones from Beemer Boneyard.  I also removed the carbon cannister about 5 years ago but both of those items are on the right side of the engine.  Any ideas?

 

[BABABeemer]

Hi John,

I’ve had a little experience with fuel leaks from that high pressure plastic manifold that goes to the fuel injectors, but they were on R1100RTs and I thought BMW had fixed the problem in the 1150s. The first bike was a 97 R1100RTP and I smelled gas, but didn’t see any drips. Finally I spotted what looked like smoke coming from a pin hole in the plastic manifold and it was finely atomized gas. I ended up replacing the fuel manifold, ( yes hard to get too but I don’t remember pulling the transmission). The replacement manifold was much heavier gauge material. The second time I bought a burned up 97 RTP from the Officer that was operating it and since the fire was mostly under the front seat and tank, I suspected that it was caused by a fuel leak in that flimsy plastic manifold. Hope you can locate where your leak is coming from.

[JohnNorCal]

So it looks like in this diagram that the fuel pressure regulator is facing front taking into consideration that there is only one manifold line.  So you were able to get to the manifold by removing the battery/motronic?

[BABABeemer]

19 minutes ago, JohnNorCal said:

So it looks like in this diagram that the fuel pressure regulator is facing front taking into consideration that there is only one manifold line.  So you were able to get to the manifold by removing the battery/motronic?

John,

As I recall you have to go in from the back and remove the air box. It involves raising the rear frame up to get to it. You definitely will need to follow a service manual to get to it. If you aren’t comfortable working on it, I have seen a guy advertise on Craigslist in Sacramento that claims to be an independent BMW motorcycle cycle mechanic that may be able to help.

[Jim Moore]

I've seen those lines leak when it gets cold out. I guess they shrink and allow leaks to form. YOu might want to try replacing all the hose clamps with 5/16" fuel injection clamps. 

 

If you decide to replace the regulator there's a mechanic on Advirder called Steptoe who says he's done it without lifting the subframe. maybe join there and ask him.

[JohnNorCal]

13 hours ago, BABABeemer said:

John,

I have seen a guy advertise on Craigslist in Sacramento that claims to be an independent BMW motorcycle cycle mechanic that may be able to help.

I have actually moved out of the Bay Area to N. Idaho.  (Updated my profile but it didn't update the post)  I might see if I can reach the clamps.  If not, will have to take to somebody who knows what they are doing.