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Leaking fuel pump, bike wont start, now what?

24K views 17 replies 3 participants last post by  MELK-MAN 
#1 ·
Hey guys! So I've been searching all forums and cannot find an answer to this... Maybe its an obvious fix but I have no idea what's going on!!

Bought a used 2006 R6S with 2400 miles on it about a month ago, everything was perfect until I started smelling some gas... Looked under the tank and to my surprise (or not) there was a tiny gas leak coming from the Fuel Pump. Apparently the previous owner "sealed" the leak on the outside of what I think is the valve for the RETURN hose (coming from the Pressure Regulator) with Marine Tex or something similar... That obviously didn't work...

So I took out the pump and wanted to order just the part where the connectors go cuz I know the pump was working perfectly, however, they dont sell that part on its own (if anyone has it please let me know). And before throwing down 60$ to 150$ on a used pump (or 700$ for a new one) I thought I'd take a chance at sealing it myself, but this time from the inside and outside with "SEAL ALL" gas and oil resistant sealant. Everything fell into place perfectly, I am no mechanic but this bike is definitely easy to work on (so far) and I feel like "I stayed at a Holiday Inn Express last nite" :lmao

Now the seal is working great, no leaks as I put the pump back in the tank. Hooked everything back up great and went to start the bike. Now when I turn on the ignition I can hear the pump starting, the bike cranks, sputters a bit, but doesnt actually catch or fully start and my battery is dying on me. Checked the main fuel line and theres fuel on both sides. Took out the "return line" from the Pressure Regulator and I see its not shooting gas out when I turn on the ignition like it was when I originally took the pump out. That "return line" is dry right now. I went to a mechanic and he said that r6's and r1's are notorious for not starting up right away once you remove fuel lines but that as long as the main line has fuel on both ends I shouldnt worry about the regulator. He said its probably air in the lines and that I should keep starting it and cranking it until it finally runs as it needs to create enough fuel pressure inside and remove all the air in the (valves or chambers, not sure what the correct word is). He said it is somewhat similar to bleeding brakes, that by continuing to start it, it will remove the air bubbles from the fuel lines just like "bleeding" the fuel lines.

Now, is this true? I dont want to continue cranking it and possibly ruining my engine or having to buy another battery. Should I continue to do this? Does anyone have any recommendations? Has this happened to anyone before?

If you look at an intake diagram (Intake diagram 2) the "return line" I am talking about is part 46 (5SL-13972-00-00). Pressure Regulator is part 24 (5SL-13906-00-00). The part I sealed would be on Fuel Tank Diagram Part 21 (Fuel Pump) but since you cant see the under side of the fuel pump on the diagram, if you look at the "FOR CAL" section it is very similar to Part 34 (only the one on my bike is facing down to the floor so you can attach the line from the pressure regulator into the fuel pump).

Please help!!
 
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#2 ·
ok.. i didn't read all that, ya need some cliff notes or something, but from what i skimmed:
There is no return line on an r6 fuel pump. those lines are overflow and vent tubes from the gas tank and cap.
the leak is likely just the rubber o-ring around the base of the fuel pump being out of place. try taking the bolts out of the ring that hold the fuel pump clamp ring, and inspect it. that o ring has a bevel to it, and if it's not in place when you seat the pump it leaks.
 
#3 ·
Cliff Notes:
2006 R6S, definitely has a return.
Sealed and Reinstalled Fuel Pump, no longer leaking.
Wont turn over.
Return Line dry, Dont see Pressure Regulator squirting fuel as it did before I took everything out.
Pump activates on ignition.
Air in the Lines?
Is there such a thing as "bleeding the fuel lines".
If u have a full minute and you can spare it try reading the detailed version... Thank you in advance brother!
 
#4 · (Edited)
air won't matter in the fuel line, as the injectors let the fuel out one end. Unlike a brake line, it's not a sealed system, so air won't matter. We pull tanks off (with the pump in there) all the time. I disconnect fuel lines for uppers and lowers after a race weekend (to get as much race fuel out) so air ? not a problem.
Now, if you don't have 47psi, that will cause running issues. when you remove the fuel line after priming, is there a good "spoosh" of fuel? or with the tank up, remove the fuel line. hook a hose to the pump outlet and point at a bucket. when you prime the pump (ignition) it should shoot a short stream of fuel for a moment.

i'm still not sold on the return line thing.. but whatever. Maybe it's a CA thing.

wont' turn over.. have you charged the battery? check the simple stuff. you won't hurt the battery cranking and recharging.
 
#5 ·
Thanks for the reply! I have not charged the battery yet, I am working with a "booster" till the bike decides to start again. What im referring to as a "return line" is the hose coming from the pressure regulatir back into the fuel pump. You can see it on "intake diagram 2" for my bike labeled as "46". Does it usually take long to get bikes started once fuel pump is removed and replaced? Now i can almost get it going but i have to play with the throttle. If i dont give it enough gas it shuts off. Same as if i give it too much. It definitely wont idle yet though, but i think its getting there.
So does it usually take this long to start em once tanks or pumps are replaced? It almost sounds as if the system is flooded, then again it might not be getting enough gas. What do you think?? :/
 
#6 ·
tank on off, pump in or out, that thing should prime and fire as if the tank was never off right away. 47psi is lots of pressure. You can NOT hold your thumb over the end of a hose with even much less psi than that. It should start right up with no issues.
silly question, but do you have enough GAS in the tank?

the symptom you describe sounds like low fuel pressure. Do you have a spare fuel pump, or tank with pump you can try from a buddy with a similar bike? or have a shop do a fuel pressure test. I have a gauge with fuel rail fittings that i cut off a spare fuel rain and a spare fuel line that i can simply connect in-line to check mine ..
 
#7 · (Edited)
Yeah, i think ure right. Im pretty sure it might be a pressure issue... The pump was working great before i took it out, and its definitely turning on. I can hear it when i set the key to ignition. Is it possible i hooked up something wrong in the pump when i took it apart. Could it be an o-ring issue INSIDE the pump? How do i get it to "establish" the correct pressure? Is there something i could do to create the correct pressure? My next step is going to be to hook up a transparent line to the sending unit to see if its shooting out with pressure. If thats not working im gonna take the pump out again and check the o-rings within the pump. Im dying here... :/ any additional sugestions? Thanks for the help! Ps: def enough gas in gas tank. Theres at least 2 gallons in there...
 
#8 ·
testing the fuel pump psi is very simple, i outlined it in an above post. you either need a tech to test fuel pressure with a gauge or get one yourself like mine in this photo..
there is no o-ring inside that went bad or anything if you didn't take the entire pump apart. There is a plastic housing surrounding the electric pump that is inside. it works, or it doesn't work. They don't last forever, and often if the tank took a good hit in a crash, they quit working.


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#9 ·
This bike has never been crashed or dropped. However, i did take the housing off the pump to seal the leak. Then put it back together... O-ring fell out of the sending unit and i had to put it back in. Im gonna test the pressure in the next few hours. If no pressure im gonna take the pump out, disassemble to check the o ring and re-assemble. Ill let u know asap. Will keep u posted.
 
#10 ·
Ok. So I hooked up a transparent line to the sending unit and placed the other end into a dumping fuel tank. At first fuel was just coming down by gravity, even when I turned the key to ignition... then I tilted the gas tank unto its left side and turned the key to ignition and the sending unit shot out a squirt of fuel, did that a couple of times in order to get most of the fuel out of the bikes tank. U said that 47 psi is a lot of pressure, and that even if I held my thumb to the line it would be hard to keep my thumb on it. When I place my thumb on the line I can feel some pressure, however, not as if to knock my thumb out of the end of the line. So I'm really thinking it might be a pressure problem. How would I re establish 47 psi? How can I make it so that the pressure is increased? Is that possible? Thanks again!!
 
#11 · (Edited)
put it this way.. if you put your thumb over one end of the hose, the other end would BLAST off the pump nipple unless held with a hose clamp. Like.. FAST. with a clamp? you would never ever be able to hold you thumb over the hose. you would get a face full of fuel spray.
Yes, if you unsnapped the 2 halves of the fuel pump white plastic housing, there is an o-ring inside at the bottom of a narrow passage.
 
#13 ·
Just spent my whole day working on the bike. Took the pump out three times. Tried putting the o-ring back in place hoping it was done correctly (not sure if its in right or not), still not enough pressure... So what's the fix? I know the pump is working, its definitely shooting out fuel on ignition, but how do I make it so it shoots out with pressure? How do I set it to 47 psi? Im sure I can do this myself... Im a little hesitant to getting raped in the a$$ moneywise for something I know is going to be simple. I know if I take it to a shop im gonna hate myself later... Any ideas??
 
#14 ·
i dont' have photos.. but if you post some i will tell you where the o-ring goes. are you sure you didn't pull the wires apart that are in there? There are a blue white and black i think that if you yank the two halves of the pump apart without disconnecting them from the other half, you will pull em out. not good.
You say the pump is working, but it obviously isn't.. now if that o ring is out of place, that will obviously cause it to not push fuel where it's supposed to go.
 
#18 ·
glad ya fixed it. with that o-ring outa place, the fuel pressure was the problem as it was likely just swirling around within the pump housing. but cool ya didn't need to get another pump..
 
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