Smell of gas when on starting after the bike has been on the side stand

[Filmcamera]

I have been noticing for the past few rides that if I park the bike on the side stand when I restart and ride off for the first few hundred meters there is a strong smell of gas.  I cannot see a leak and I do not get that smell at any other time, nor does the level of gas in the tank seem to make any difference.  My gas mileage seems about the same as always, though I am mainly using the bike for short rides up and down my hill to the gym or shops etc so the mileage always sucks doing that.  Has any one else had this and found out what caused it?

[Martin]

Check the vacuum line that goes to the FPR for signs of fuel.
Regards Martin.

[daveson]

Any sign of fuel in either of the two tank vent lines?

Is it more so when the tank is full?

[Filmcamera]

Martin - no obvious signs of fuel in the vacuum line but I did notice it does not have any kind of clip to keep it in place and it disconnects very easily.  There is a slight discoloration around the bottom of the vacuum tube entry point on the throttle body as you can see in the photo
 




Daveson - both the tank vents empty into the little cup that sits in the corner of the frame under the tank - it is dry as a bone and dusty so I do not think it had had any fuel in it recently.


I would have said it is the same no matter what the fuel level but actually at this moment the tank is very empty and I have not been able to reproduce the issue at home.  There again all I have been doing is letting the bike idle for a bit then turning it off, putting it on the side stand, waiting a couple of minutes and starting it up again but so far doing that nothing.

[johnny]

greetings...

i has had this and found out what caused it...

the smell of gas was coming from the gas...

j o

[SDCR john]

I recently had a similar issue, that only revealed itself, when on the side stand. After a checking the tank lines, I discovered that the fuel line that comes off of the fuel rail, had a bad BMW clamp, where the fuel line enters the FPR. The crimp in the clamp, had gotten slightly loose, and a small amount of fuel was escaping. and dripping. I noticed when it was on the side stand, I could see the fuel drip down on the  exhaust.

Very glad that I found this when I did. My fix, was a 10 mm BMW screw type clamp, as well as a new piece of fuel injection rated hose.

 

I have been noticing for the past few rides that if I park the bike on the side stand when I restart and ride off for the first few hundred meters there is a strong smell of gas.  I cannot see a leak and I do not get that smell at any other time, nor does the level of gas in the tank seem to make any difference.  My gas mileage seems about the same as always, though I am mainly using the bike for short rides up and down my hill to the gym or shops etc so the mileage always sucks doing that.  Has any one else had this and found out what caused it?

[stokester]

I had the same situation but was able to determine the leak was coming from the area of the fuel pump regulator.  After removing the airbox I found the fuel line connection to be loose.  I bit the bullet and replaced the lines using Oetiker clamps on the FPR fuel lines.
It would certainly be possible that a leak around the FPR would be so small that a leak would be small enough to evaporate before being noticed.
Removing the airbox to get a good look at the FPR connections is a good start.

[SDCR john]

Stokester, Sounds like our Bricks had similar issues, as mine was leaking a very small amount of fuel, that was pushing past the Oetiker clamps at the fuel pressure regulator, while under pressure. After seeing the the Oetiker, had worked itself loose, I decided to go with the other, screw type clamp. Granted, the Oetikers on my bike were probably the originals. I plan on going over all of the other fuel line a R&R this winter.

I had the same situation but was able to determine the leak was coming from the area of the fuel pump regulator.  After removing the airbox I found the fuel line connection to be loose.  I bit the bullet and replaced the lines using Oetiker clamps on the FPR fuel lines.
It would certainly be possible that a leak around the FPR would be so small that a leak would be small enough to evaporate before being noticed.
Removing the airbox to get a good look at the FPR connections is a good start.

[stokester]

Stokester, Sounds like our Bricks had similar issues, as mine was leaking a very small amount of fuel, that was pushing past the Oetiker clamps at the fuel pressure regulator, while under pressure. After seeing the the Oetiker, had worked itself loose, I decided to go with the other, screw type clamp. Granted, the Oetikers on my bike were probably the originals. I plan on going over all of the other fuel line a R&R this winter.

Yes, after finding cracks at the bends on the exposed fuel line I replaced all of them to include the vacuum line to the FPR which was hard and brittle.  The OEM pre-formed lines are expensive but have lasted 25 years so I opted to replace all of them in both my K75s.  Others have had success with standard high-pressure fuel lines.  One of the last things I want on a trip is leaking fuel, especially at the hidden FPR.  I used the Oetiker clamps because I've got the proper pliers/pincher.

[billday]

The pre-formed lines are so worth it.

Note,  you don't have to use oetiker clamps (and buy the tool), but if you use screw clamps make sure you get the right kind, hardware store worm clamps won't get the job done.

[cycleman]

Gas could be leaking by the filler cap and running down the left side of the tank when the bike is on its side stand. This would only happen with a full gas tank. This was happening to me so I rebuilt the cap and put a new flange gasket on the gas tank. No more leaks.