Hi, My 94 1100LT is causing a strong smell of fuel. Whenever I enter the garage its very strong. It happens more after the bike is run but is generally there all the time. I have replaced every external fuel line with the correct pipe from James Sherlock BMW. There is no physical evidence of fuel anywhere on the engine or under the tank or injector area. The smell seems to come mainly from around the filler and also from under the rear of the tank area. However, it is more just an overall smell of Gas and not specifically from single points. At some time in the past a Newton Equipment Aircraft filler has been fitted and I was wondering if this could be the cause. There is a large rubber gasket between the Newton filler and the tank and I was wondering if this is blocking a hole that may have been there to vent the original filler area. I put it in a van to take for the MOT test this week and the smell was more than a little noticable in the cab which is completely seperated from the load area. The bike runs just fine although a little smokey after being laid up for 7 years. It seems to be reported in this forum that may clear up after a while.

The smoke will clear up - it's just stuck rings.

Pull the filler cap and check for a small hole at 9-oclock in the gasket. If it's not there, lift the gasket and you'll see it. However, not having the hole is more likely to cause an airlock in the tank rather than a putative leak. Having said that, if any paint has lifted under the gasket, it may just be creating a hole big enough to let the smell of fuel escape. Worth checking at least.

I had a problem like that, a smell of fuel in the garage. Couldn't see a leak cause it was at a hard to see place. In my case it was the O-ring where the pump is installed to the tank. It was permanently compressed after years of compression, so leaking.

There is a overflow vent on the ring around the edge of the cap. The overflow goes to a black rectangular cup or a hose under the tank and then goes down a hose that exits near the RH footpeg. If the cup or hose is absent when the fuel expands it will bypass this system and drip onto the hot engine which could give you the odor.

Thank you all for the replies. I've had the tank off many times and the small cup and overflow pipe is in place. If the vent hole at 9 oclock is blocked by the Newton cap gasket, I'm thinking that it might prevent the smell rather than encourage it. Dai, are you suggesting that a vacuum might build up in the tank if the hole was blocked? I'm a little confused as to why there are 2 pipes under the tank going into the aforementioned cup, I think one is from the cap in case of filling spillage, but I'm not sure of the other. Daveyson, was the leak you had coming from under the tank? I'm not sure where the O ring is you mentioned on the fuel pump. I've not removed the fuel pump from the tank.  I've noticed that the garage does'nt smell after a coupe of days without the engine running. Run the engine and it smells again. I understand that the pressure in the fuel pump and injector rail might stay for some time after the engine has stopped running and am wondering where this pressure goes as it leaks away. Could this be the culprit in some way?

Of the two overflow pipes on the r/h side of the tank, the rear one drains any water in the filler cap area and the forward one drains any fuel overflow. Yes, if the fuel drain hole is blocked then a vacuum will build up. If it gets bad enough the tank will collapse; a running fuel pump can build up a fair amount of vacuum, unlike a carb-equipped bike which will just quit. I've seen it happen*, so it's not some internet rumour.

I think Daveyson means the fuel level sensor at the back of the tank.

You may not have the California Cup that MartinW mentions (yes, I know he's an Aussie!). I know what they are but I've never yet seen one on a UK flying brick. You're more likely to have either no drain tube or a drain tube that vanishes somewhere down by your right foot. If that has a split in it the end result will be much as Martin suggests.




*To me, much to my shame. I put the gasket back in arse-about-tit. Although the tank did blow back out when the vacuum was released, it maintained a small crease on the l/h side for the rest of its life.

The rear pipe is the one for the gas cap drain hole. The front one is fuel venting.

Corrected - thank you for catching that