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Thread: fuel pump failure?

  1. #31
    Registered User roger 04 rt's Avatar
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    Quote Originally Posted by AntonLargiader View Post
    It's good to do, but then make that an inspection on its own merit, not something piggybacked onto something else that doesn't really need to be done.

    ... Changing the filter is easier when its outside the tank, period.

    And most bikes can go pretty much forever on the original in-tank lines if the bike is in regular use. In the cases where they don't, it's damage caused by very old fuel or some sort of contaminant. Not mileage-related, so no correlation to 24k mile filter change interval.
    I accept that its easier to change the filter outside the tank. But using your own reasoning isn't moving it outside the tank something that really doesn't need to be done? And there's still my original concern that fuel system designers know more than me. Since it's obviously easier to change on the outside, what did BMW know leading them to put the filter inside the tank?

    I'm interested in your comment that the fuel lines go forever unless attacked by very old fuel. The three hoses inside my tank looked fine to the eye, even knowing that I'd had a catastrophic failure. Since the pump can output about 120 liters per hour but the engine consumes less than 40 liters per hour at maximum horsepower, there could be plenty of leaking hoses without most being able to know.

    I assumed that ethanol was a contributing factor to the damage of my in-tank hoses but it could be that a prior owner had used some non-ethanol additive one winter (methanol or isopropyl based?). My point in bring that up is that in a fleet (1100/1150) of 10-20 year old motorcycles, hose failure is a bogeyman--one minute you're running, the next you're dead in the water.

    RB

  2. #32
    . AntonLargiader's Avatar
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    I have no way of knowing, but I suspect the filter location is driven by packaging more than anything else. Sure there's a lot of room and stuff going on within the R11RT fairing but the arrangement is still kind of primitive. It wasn't until the Hexheads that we saw nice hose routing, canisters integrated into tanks and fairings, etc. On the ST, maybe there was simply more room for it outside the tank, and on other bikes there's more room inside. F650 is also outside the tank, and in a very easy to access location (under the front of the seat, where it is on my wife's R11GS). So to isolate the "is it safe" issue, my interpretation is that BMW thinks it is safe.

    Personal preference for the location, I think we can leave that at personal preference.

    As for the hose issue, I've seen hoses that have literally melted on old derelict bikes. The fuel is like turpentine, and the hoses come out smearing black goo on everything they touch. Same with the rubber fuel pump dampers. Bikes of the same age where the fuel stays fresh do not experience this. Thinking back to internal hoses that I've replaced, they are:

    - bikes that have sat for years (generally older ones with less sophisticated vapor control where a lot of moisture gets into the tank)
    - bikes where the wrong hose material was used inside the tank as a replacement for the original hose

    That's about it. Your experience with a newer bike that presumably was in regular use, unmodified, is a real outlier. I can understand your feelings about checking the lines, but that situation is not representative of the general population of bikes in my experience.
    Anton Largiader 72724
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  3. #33
    Registered User roger 04 rt's Avatar
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    Quote Originally Posted by AntonLargiader View Post
    I have no way of knowing, but I suspect the filter location is driven by packaging more than anything else. Sure there's a lot of room and stuff going on within the R11RT fairing but the arrangement is still kind of primitive. It wasn't until the Hexheads that we saw nice hose routing, canisters integrated into tanks and fairings, etc. On the ST, maybe there was simply more room for it outside the tank, and on other bikes there's more room inside. F650 is also outside the tank, and in a very easy to access location (under the front of the seat, where it is on my wife's R11GS). So to isolate the "is it safe" issue, my interpretation is that BMW thinks it is safe.

    Personal preference for the location, I think we can leave that at personal preference.

    As for the hose issue, I've seen hoses that have literally melted on old derelict bikes. The fuel is like turpentine, and the hoses come out smearing black goo on everything they touch. Same with the rubber fuel pump dampers. Bikes of the same age where the fuel stays fresh do not experience this. Thinking back to internal hoses that I've replaced, they are:

    - bikes that have sat for years (generally older ones with less sophisticated vapor control where a lot of moisture gets into the tank)
    - bikes where the wrong hose material was used inside the tank as a replacement for the original hose

    That's about it. Your experience with a newer bike that presumably was in regular use, unmodified, is a real outlier. I can understand your feelings about checking the lines, but that situation is not representative of the general population of bikes in my experience.
    Thanks for your thoughts on these issues. You've seen many more of these bikes than I have but I've come across threads with other experiences like mine, photo below. Just before I bought my bike the dealer had opened the tank and replaced the filter as part of the prep. The hoses weren't replaced but presumably looked fine.

    Six months later when one of the hoses ruptured. I open the tank, took one look at the hard, tired hose going from the fuel pump to the fuel plate and thought it was the culprit. The other hoses attached to the fuel filter looked fine. I'll bet I handled the fuel plate for a couple days before I realized that the reason the fuel filter hoses looked so good was that they were, almost invisibly, weeping fuel. It wasn't until I cut the hoses in half that I found the actual split that caused failure about 5 days into the project. The hose from the pump was hard but not cracked.

    Because the cracks are quite hard to see and because the pump has 3.5 times the capacity needed for WOT and almost 10 times the capacity for normal riding, I would believe that my hoses aren't outliers and that there are lots of slightly leaking hoses in the fleet.


  4. #34
    . AntonLargiader's Avatar
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    Might have to do with hoses drying out in the air after being used in fuel. Just speculating.

    Testing the fuel pressure (per BMW) involves observing the bleed-down of pressure. That will catch the problem you had. Sometimes the leak is so great that the system never gets up to pressure, and sometimes it just leaks down too fast. A good system holds pressure for quite a long time.
    Anton Largiader 72724
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  5. #35
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    Quote Originally Posted by AntonLargiader View Post
    It's good to do, but then make that an inspection on its own merit, not something piggybacked onto something else that doesn't really need to be done.

    Sure an external filter can fail, but burst filters are pretty much nonexistent after the design changed from the crimped edge to the soldered edge many years ago. It would be much more likely to have a fuel leak from a cracked QD fitting, cracked distributor pipe, leaking external line or leaking flange. You're combining unrelated things for convenience. If the filter is safe outside the tank, then it's safe outside the tank. If you should go in to check the fuel lines, then you should go in to check the fuel lines. Changing the filter is easier when its outside the tank, period.

    And most bikes can go pretty much forever on the original in-tank lines if the bike is in regular use. In the cases where they don't, it's damage caused by very old fuel or some sort of contaminant. Not mileage-related, so no correlation to 24k mile filter change interval.
    +1, on all counts.
    Ride Safe, Ride Lots

  6. #36
    Registered User roger 04 rt's Avatar
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    Quote Originally Posted by AntonLargiader View Post
    ...
    Testing the fuel pressure (per BMW) involves observing the bleed-down of pressure. That will catch the problem you had. Sometimes the leak is so great that the system never gets up to pressure, and sometimes it just leaks down too fast. A good system holds pressure for quite a long time.
    You wrote in another post about over-maintained valves and throttle bodies (IMO, because we can) and I would add, under-maintained fuel systems (because they tend to be invisible until they fail). A good use for plastic QDs from 1150s after replacing them with metals is the kit below. In addition to pressure leak down (mine tests at about 44 and holds about 40 psi for days) is return volume. If you measure the amount of fuel returning to the tank at idle, a good system returns about 2 liters per minute. If you get that amount, most likely pressure, pump, hoses and filter are all good. It's an effort to get the gauge, hoses and put it together but well worth it.

    The Kit


    Pressure at Idle


    Holding pressure, motor stopped

  7. #37
    Registered User roger 04 rt's Avatar
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    This from yesterday's news:

    Quote Originally Posted by Phil
    Last Saturday my 2002 R1150RT suddenly started sputtering and backfiring while cruising down the freeway. The bike would not run above an idle. If I tried to give it more gas, it just sputtered. After eliminating a few other possible causes I found one of the hoses inside the fuel tank had cracked. Based on my experience I would recommend anyone with a fuel injected bike to change out the in-tank fuel hoses every five years or so. Since you've disassembled the tank you might as well change the fuel filter, strainer, and pump vibration damper. Below is a picture of the hose with the crack.

  8. #38
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    thought it was the fuel pump, but no...

    Quote Originally Posted by aapasquale View Post
    Hi all-
    Just got back from a trek to Bob's BMW in Maryland. Had SS braided brake cables and bar-backs installed on my 1994 R1100RS--drove back and forth from east end of Long Island (about 600 miles)--when within 1/4 mile of my home, bike just stopped and would not restart--battery good, fuses good--cranks well but doesn't turn over--when turning switch on, I don't hear that familiar whirring sound of fuel pump bringing fuel line up to pressure--I'm assuming this is a fuel pump problem--bike has 40,000 miles--any other suggestions before I call Beemer Boneyard and others for a replacement? Thanks in advance for your input.

    Tony

    PS--Bob's is very good--worth the trip--traffic in that area is unbelieveable!
    My 02 r1150r quit on the road, suspected fuel pump as bike didn't sound right on cranking. Read all the posts concerning pump, ordered pump from beemer bone yard. With the tank off tested pump with jumper wires, oh oh, pump sounded fine. Phoned closest dealer for service appointment , three week wait time. Went back to posts looking for clues. Tried reversing pump connections maybe flush something out. Disconnected and reconnected motronic unit, put everything back together for trailer trip. Gave it a crank, why not. It fired up, test ride, so far so good. Now have a spare pump, but won't cancel dealer appointment just yet. Thanks to all for tips on Forum, hope this helps someone else. Glenn Bolder, Rosseau Ontario.

  9. #39
    MOA,RA,ABC,AMA,TT,MOAL brownie's Avatar
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    Unhappy ...same as Roger

    Exact same situation as Roger last week....possibly original fuel hose split, loss of pressure, sputter, die.......dealer replace all...runs fine!!!!
    Heed NEAD: No Egos, Attitudes, Distractions!!!!!
    Shep Brown MOA 27510
    "Igor" 82 RS "Inga" 04RT
    Pensacola, Flairider

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