Losing all tank fuel out overflow tube

General discussion of the BMW R1200RT/R1250RT
Post Reply
exupawi
Posts: 6
Joined: Thu Dec 07, 2023 4:32 am
Bike Model and Year: 2007 BMW R1200RT
United States of America

Losing all tank fuel out overflow tube

Post by exupawi »

I've been fighting one fuel issue after another.
1st issue - fuel regulator went out about a year ago. I saw the post on youtube about bypassing it. I performed the work around and it seemed to work fine.
2nd issue - 90 degree plastic quick connect
Fuel fitting cracked, spewing fuel. Replaced it, resolved that issue.
3rd issue - fuel leak around fuel pump housing ring on tank. Had a pin hole in tank. Resolved with super glue.
New issue - Went for about a 30 mile ride, no issues with performance. Parked in the garage, smelled fuel. There was another fuel leak, it was coming from the overflow tube. When i took the tube off, fuel was streaming out the tube nozzle, like a water fountain. I cut a piece of the tube off and put it back on. I went out a bit later to check on it, it had dumped about 5 gallons on the garage floor.
So, I'm wondering whether this could be a faulty fuel pressure regulator issue , some tank pressure vent issue, or maybe something related to that fuel regulator bypass? Any suggestions would be appreciated.
User avatar
Doctor T
Posts: 1670
Joined: Tue Dec 21, 2021 10:21 pm
Location: west sussex
Bike Model and Year: 2007 R1200RT SE
Has liked: 909 times
Been liked: 239 times
Great Britain

Re: Losing all tank fuel out overflow tube

Post by Doctor T »

Sounds like a valve is faulty or there is too much pressure in the tank. Does you pump turn off when you turn the bike off?
Trust me I am a retired Doctor and lecturer at Oxford University of Structural and Mechanical/Electrical engineering.
exupawi
Posts: 6
Joined: Thu Dec 07, 2023 4:32 am
Bike Model and Year: 2007 BMW R1200RT
United States of America

Re: Losing all tank fuel out overflow tube

Post by exupawi »

Doctor T wrote: Thu Dec 07, 2023 2:31 pm Sounds like a valve is faulty or there is too much pressure in the tank. Does you pump turn off when you turn the bike off?
Well, not sure what valve could be faulty. When I turn off my bike i also have to turn off the fuel pump (with the workaround I have).
I checked it this morning, my switch for the fuel pump is working correctly. So, the pump is definitely not running when the fuel starts
pushing out the vent tube. When this was occurring, I did open my fuel cap, but there didn't seem to be any pressure in the tank.
So, something is causing this back pressure, pushing the fuel out the vent tube, while the bike is off.
User avatar
Doctor T
Posts: 1670
Joined: Tue Dec 21, 2021 10:21 pm
Location: west sussex
Bike Model and Year: 2007 R1200RT SE
Has liked: 909 times
Been liked: 239 times
Great Britain

Re: Losing all tank fuel out overflow tube

Post by Doctor T »

I see you in the USA. Do you have a carbon canister fitted for the emissions?. This is faulty can cause back pressure
Trust me I am a retired Doctor and lecturer at Oxford University of Structural and Mechanical/Electrical engineering.
exupawi
Posts: 6
Joined: Thu Dec 07, 2023 4:32 am
Bike Model and Year: 2007 BMW R1200RT
United States of America

Re: Losing all tank fuel out overflow tube

Post by exupawi »

I purchased this bike a couple years ago, but seems it must be bare bones. It does not have any emissions carbon canister.
The rubber tube from the fuel pump assembly just goes directly under the bike, for drainage i guess. The tank does have a vent by
the fuel inlet. I took it out and blew through it, but hard to say whether it's working correctly. I may purchase a new one, just
to eliminate that as a possibility for the pressure issue. I'll take the pump assembly out and inspect it. Not sure whether there
is anything else on this bike that controls the tank pressure, other than that vent by the fuel inlet.
User avatar
Doctor T
Posts: 1670
Joined: Tue Dec 21, 2021 10:21 pm
Location: west sussex
Bike Model and Year: 2007 R1200RT SE
Has liked: 909 times
Been liked: 239 times
Great Britain

Re: Losing all tank fuel out overflow tube

Post by Doctor T »

Not being funny but have you connected the right hoses to the correct fitting
Trust me I am a retired Doctor and lecturer at Oxford University of Structural and Mechanical/Electrical engineering.
exupawi
Posts: 6
Joined: Thu Dec 07, 2023 4:32 am
Bike Model and Year: 2007 BMW R1200RT
United States of America

Re: Losing all tank fuel out overflow tube

Post by exupawi »

Yes, everything is plugged into what it should be. I ordered a tank vent/valve. Not sure, it that will solve this pressure problem, but
we'll see
JustmeandtheRT
Posts: 15
Joined: Thu Sep 01, 2022 10:57 pm
Location: Denver's colorado usa
Bike Model and Year: 2005 R1200RT
Been liked: 2 times
Germany

Re: Losing all tank fuel out overflow tube

Post by JustmeandtheRT »

:-D I certainly didn't have something plumbed properly lost 2 of 4 gal i just added after installing the tank i put my fuel pump vacuum to fuel filler vent whats the proper route for everything 05 r1200rt abs cruise charcoal canister aswell
Post Reply