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#789750 - 07/15/12 06:33 AM Re: BROKEN DOWN on side of road - Here's a Thrill [Re: roger 04 rt]
Jim Moore Offline
Member

Registered: 12/31/00
Posts: 2449
Loc: Jax, FL
Originally Posted By: roger 04 rt
Given that the internal hoses appear to have been submersible, but old, I believe they should be part of a period ice service checklist.


Good job. I'm glad you got it figured out. I think you simply got a bad piece of fuel line. I also think it's pretty rare. Fuel line is generally pretty tough. I used non-submersible line from the auto parts store inside my tank when I externalized the fuel filter on my RT. I didn't know any better. It still looked brand-new many years and many tens of thousands of miles later.
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Jim Moore Jax, FL '99 R1100S '02 R1150GS

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#789780 - 07/15/12 08:58 AM Re: BROKEN DOWN on side of road - Here's a Thrill [Re: Jim Moore]
roger 04 rt Offline
Member

Registered: 11/27/11
Posts: 1872
Loc: Massachusetts
Originally Posted By: Jim Moore
Originally Posted By: roger 04 rt
Given that the internal hoses appear to have been submersible, but old, I believe they should be part of a period ice service checklist.


Good job. I'm glad you got it figured out. I think you simply got a bad piece of fuel line. I also think it's pretty rare. Fuel line is generally pretty tough. I used non-submersible line from the auto parts store inside my tank when I externalized the fuel filter on my RT. I didn't know any better. It still looked brand-new many years and many tens of thousands of miles later.


As I waited for parts I came across another post you'd made on the topic and knew that you'd inadvertently put non-submersible fuel hose in your tank but hadn't had a problem, I accept your observation.

What I would say to that is that all three of the hoses, that I now believe are original, were degraded--time, heat, gasoline and alcohol exposure. The hose coming from the fuel pump was in the worst physical condition but not leaking. The other two hoses look almost new until you examine them closely. I believe that many motorcycles will have similarly degraded hoses in the tank unless they've been replaced.

I just looked up the pump spec which is 110 liters per hour at 43 PSI, the pressure our bikes run at. Our injectors have a maximum flow of 350 cc/min so two of them can flow 750 cc/min or 45 liters/hour. Cruising at 75 MPH requires 20% of the injectors max flow (or a little less) that's about 9 liters/hour.

So the hoses inside the tank could be leaking at the rate of 70 liters per hour and you'd never know it.

I don't believe the situation I found is unique. At the same time I'm not surprised that, as of yet, you haven't had a problem.


Edited by roger 04 rt (07/15/12 08:58 AM)

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#789781 - 07/15/12 09:14 AM Re: BROKEN DOWN on side of road - Here's a Thrill [Re: roger 04 rt]
roger 04 rt Offline
Member

Registered: 11/27/11
Posts: 1872
Loc: Massachusetts
For those who want to make a fuel system test of an R1150RT to check its condition, here's a straightforward method based on the numbers in the last post (fuel pump delivers 110 liters/hour at 43 psi). Other systems may have different numbers.

Put a fuel pressure gauge in series with the high pressure line.

Take the return line and route it through a hose with a QD into a fuel container. Take all appropriate safety precaustions and have a proper fire extinguisher on hand. Do this outside if possible.

Start the motor and let it idle for two minutes exactly, then shut off the engine. You should have just under 1 gallon in the container. The fuel pressure during idle should read 43 PSI plus or minus 4 PSI.

Feel free to check the numbers, I'll be testing my system later this week or next.


Edited by roger 04 rt (07/15/12 09:17 AM)

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#789860 - 07/15/12 02:08 PM Re: BROKEN DOWN on side of road - Here's a Thrill [Re: roger 04 rt]
waynerd Offline
Member

Registered: 07/09/09
Posts: 136
Loc: Westminster, Colorado
Hi Roger,

I took a trip up north to my favorite, independent shop yesterday to get some maintenance parts. They have a decent selection of repair parts, but nothing like a dealer. When I asked about the U-tube inside the tank, they pulled out a box-full of new ones. They said that failure is kinda common. Which I think is telling as they haven't always been in step with other issues that I've read about on this forum (stick coils). Dang, BMW is rather proud of that little piece of rubber - $36.

Thanks for your meticulous report of this issue and resolution. I hope that I'm sneaking up my knocking issue (even if it is rather slowly...)
_________________________
Wayne
"High-Town" Crew
'04 1150 RT
'84 V65 Sabre (crate baby)

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#789887 - 07/15/12 03:55 PM Re: BROKEN DOWN on side of road - Here's a Thrill [Re: waynerd]
roger 04 rt Offline
Member

Registered: 11/27/11
Posts: 1872
Loc: Massachusetts
Thanks waynerd.

I got the chance today to split and study the hoses and see where the specific leaks were occurring. In the photo below you can see three splits:

--The worst, that I believe led to the breakdown, was in the U-shaped hose. It's a crack over 3/4" long on the inside and 1/2" on the outside.

--Also there were two splits on the hose going to the filter input each about 3/8" long on the inside and 1/8" and 1/4" on the outside.

It seems unlikely to me that all three splits occurred at the same moment. Most likely I've been driving for a long while with leaking "innards". It also leads me to conclude again that other bikes are likely to have this condition.

As long as the leaks are small enough that the fuel pressure remains around 43 psi which means that not more that 60-70 liters per hour (gulp!) are leaking internally, the motorcyle operates normally. Finally, one tears open and a catastrophic failure occurs.



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#789894 - 07/15/12 04:28 PM Re: BROKEN DOWN on side of road - Here's a Thrill [Re: roger 04 rt]
oldironhead Offline
Member

Registered: 06/08/11
Posts: 85
Loc: North Carolina
Cracks or splits similar to those in the hoses in my tank are what motivated me to go with the Gates submersible hose and the steel curved piece. I can't guarantee that the Gates stuff is better than the German stuff, but it's widely used in automobiles, and I don't hear much about it failing. Plus, making a steel u shaped line was cheaper than that expensive curved piece.


Edited by oldironhead (07/15/12 04:29 PM)

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#789896 - 07/15/12 04:32 PM Re: BROKEN DOWN on side of road - Here's a Thrill [Re: roger 04 rt]
dirtrider Offline
The Oracle
Member

Registered: 06/05/10
Posts: 8516
Loc: Ohio
Afternoon oldironhead

Lots of hose failures in the automotive fuel tanks in the past. Most have now gone to a nylon or Teflon based plastic hose to prevent issues with inside tank failures due to fuel additives or alcohol in fuel.
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D.R. ___
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#790006 - 07/16/12 06:56 AM Re: BROKEN DOWN on side of road - Here's a Thrill [Re: dirtrider]
roger 04 rt Offline
Member

Registered: 11/27/11
Posts: 1872
Loc: Massachusetts
Originally Posted By: dirtrider
Afternoon oldironhead

Lots of hose failures in the automotive fuel tanks in the past. Most have now gone to a nylon or Teflon based plastic hose to prevent issues with inside tank failures due to fuel additives or alcohol in fuel.


I didn't have the time or access (where I'm located at the moment) to do this research but I believe such a kit would be great. I believe that about 4" of such a hose would make the bend from filter to plate.

As I mentioned the pump spec is 110 liters per hour at 43 PSI. What I haven't seen is its maximum pressure if, say, the QDs have been disconnected and the pump is activated. Under that scenario perhaps an aged hose could split, like mine did.

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#790010 - 07/16/12 07:06 AM Re: BROKEN DOWN on side of road - Here's a Thrill [Re: roger 04 rt]
roger 04 rt Offline
Member

Registered: 11/27/11
Posts: 1872
Loc: Massachusetts
I've just ordered a fuel pressure gauge that should be delivered this week, and "Caddis" who just replaced a set of QDs has offered to ship the old ones to me.

My plan is to take the gauge, plug it into a T-fitting, and add a male & female QD with hose to the other two ends of the T-fitting. I would plug that into the high pressure feed hose at the bike Quick Disconnect.

Then I would take another hose, add a QD to one end, connect it to the return side of the pressure regulator and put the hose into a fuel container.

I will then either start the bike or jumper the fuel pump relay and measure the amount of fuel that gets pumped into the container in one minute (should be about a half gallon). The supply pressure would be measured during pumping.

If the pressure is in spec, 43 psi plus/minus 4 psi, and the volume is about a half gallon (3 lbs.), the fuel pressure/volume system is functional and very likely the internal hoses are leak-free


Edited by roger 04 rt (07/16/12 07:08 AM)

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#790747 - 07/19/12 03:59 PM Re: BROKEN DOWN on side of road - Here's a Thrill [Re: roger 04 rt]
roger 04 rt Offline
Member

Registered: 11/27/11
Posts: 1872
Loc: Massachusetts
Today I put together a fuel pressure gauge and flow-volume testing setup to create a baseline for my R1150RT. The spec for the pressure regulator is 43 psi and the fuel pump is rated for 110 liters per hour.

Here's a photo of the fuel pressure gauge connected to two QDs salvaged from a plastic to metal QD conversion. And a female QD connected to a collection hose. The idea is to connect the fuel gauge to the high pressure feed hose, and connect the collection hose to the regulator side of the return line so that fuel bypassing the fuel pressure regulator is collected in the container and weighed. This way you can measure both the fuel pressure and total fuel volume.

In order to develop 95 HP (R1150 Max.), the system has to be able to output a minimum of 35 to 40 liters per hour.


Here is the system connected to the motorcycle.


Here is the idle fuel pressure, 44 psi.


I ran the motorcycle for 60 seconds and collected 3 lbs. 13 oz. of fuel which equates to 0.64 gallons (6 lbs. per gallon), which translates to 145 liters per hour. Much better than the pump spec of 110 l/h and easily 3 times the amount required to produce full power. Every 10 minutes the pump runs 5 gallons of fuel through the system.

Thinking back on the failure of my system and the multiple cracks in the hose. I suspect that my system was running fine with some leaks but then one opened to the point where there was little to no fuel pressure. If I'd been measuring pressure and volume once a year I might have caught this long ago.

The 145 l/h will serve as a baseline for future measurement to assess the health of the fuel delivery system including pump, filter and internal hose condition.

As a side note, the new pump is noticeably quieter than the old one. Also the engine is noticeably smoother (am I imagining this?) Which I believe is due to the better injector matching (< 2%) after cleaning.

RB

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