fuel overflow

[bazzjazz]

Hi all,

I have a US import 1995 R1100GS and successfully performed a 'canisterectomony' on it a few years ago. So both narrow lines coming from the tank hang loose behing the footpeg with no problems...until recently.

When I fill up now, not to the brim, but even just to approx 70% capacity, I get a steady drip of fuel out of one of these lines. This can continue for maybe 50-60 miles.

I understand one of the lines is connected to the overflow in the filler cap (and I haven't drilled out the neck for extra capacity) and this is to drain off excess fuel trapped when filled or for water caught in the recess after heavy rain/washing, so I am assuming that this is not the problem.

The other line, I think, originates in the tank and is connected to a black, oval shaped float-like thing, which is is a fixed position. Is this the breather line to equalise the pressure in the tank and stop a vacuum forming?

This line must be what is causing my problem as there is a prolonged dripping but does anyone have an idea how this could be happening??

Thanks for the help.

Barry
95R1100GS

 

[Fanum]

Barry....have taken the liberty of cross posting this to the Advrider site over in Merika....a good proportion of them have done Canisterectomies......Not something we come across over here much I would have thought.....

watch this space....


PS It's HERE

 

[bazzjazz]

Thanks, Fanum, although I have a feeling that the canisterectomy might not be the cause of the problem.

If I still had the canister, the excess fuel would be clogging up the charcoal. I think the problem is inside the tank, possibly with the 'float thing' I described or maybe with a leaky connection on the hose inside the tank.

Thanks for the reply.

Barry

 

[ferguscawley]

Excuse my ignorance, but WTF is a Canisterectomy ??

 

[bazzjazz]

All US GS's come with a 'canister' attached to the rear right side of the bike near where the brake fluid resovoir is.

The overflow from the tank is connected to this so if there is excess fuel coming from the tank, it flows into the canister, which is full of charcoal, instead of out the hose and onto the ground. This is done for environmental reasons.

But the overflow is also the breather pipe, I think???? So if the canister clogs up it can lead to a vacuum in the tank (this is where I'm guessing...)

So, a canisterectomy is removal of said canister, instructions for which are on the ibmwr site somewhere. Removing the canister is one of those things that are debatable as to their merits. I just felt like it.

So now you know

So any ideas why my tank might be overflowing?

cheers,

Barry

 

[Mick Fagan]

Both hoses are in the fuel tank and the one which is the overflow from the visible hole in the recessed fuel cap reservoir, goes from the top of the tank to the inside of the fuel pump/filter assembly.

There it is clamped onto a smallish (10mm OD?) metal pipe which transfers to the outside of the tank where another hose is clamped onto the end of the metal pipe. This hose then on Australian and I guess UK bikes, ends above the rear swinging arm where it deposits said overflow fuel onto the bike and then the ground.

Thinking about your situation, it could possibly be that this hose has cracked near the top and is letting fuel into the inner so it can flow to the outer, if you get my drift.

I would suggest that it's time for a fuel filter change on your bike, and, at the same time, either a replacement of the overflow pipes, or, at least a thorough check of all inner pipes.

This hopefully will clear, what appears to me, to be an extraordinary fire hazard, let alone a health hazard!

To thoroughly check this out you will have to remove your fuel filler cap hardware. This will entail you using a Torx socket and I would suggest that you also purchase a new rubber 'O' ring for the filler cap to tank seal. I've never been able to make any used rubber 'O' ring fit, after being dissambled due to the rubber ring absorbing petrol and expanding upon being released from it's captive groove.

Mick.

 

[Mick Fagan]

Barry, I've just re-read your last posting and the breather pipe is another pipe.

You'll find this pipe when you take your fuel filter/pump assembly off.

It also goes to the outside world via the same route as the above mentioned pipe in my last posting. It is right alongside the cap overflow one, on the filter/pump assembly firewall.

Mick.

 

[bazzjazz]

I have the fuel cap assembly takne off so will check the hose condition and connections.

A reply on advrider also suggests the oval shaped float can come loose easily on the early GS's and let fuel into the pipe and so this could also be the potential problem.

I'm off to the garage now, armed with a lot more info than I had yesterday, so many thanks for all the suggestions!

I'll post the results when I'm sorted!

cheers,

Barry

 

[MikeO]

If you're removing the plate from the tank to get access to the pump & filter, consider moving the filter outside. This will allow you to replace the fuel filter (due at 24k service intervals) in 5 mins...

Mike

 

[bazzjazz]

Everything is back together again now, so moving the fuel filter is a job for another day!

I checked the hoses which seemed to be fine and made sure that the oval shaped float was seated snugly and put it all back together.

A trip to the garage to fill it to the brim and a short spin later and everything seems to be fine. It would have been leaking previously, but there's no drips at all. Success!

Thanks for all the helpful suggestions.

cheers,

Barry