Author Topic: Fuel Pump (new idea?)  (Read 2856 times)

ElGuapoLoco

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Fuel Pump (new idea?)
« on: Mar 31, 2019, 07:45:53 am »
Been reading on here...  It seems if you run your tank too low you might have a very expensive problem.

Has anybody tried simply replacing the high-dollar and problematic stock pump with a generic?

It would be relatively easy to "gut" the standard pump then break into the line between the secondary tank where the pump is and the fuel rail, installing a generic pump there - something like this:  https://www.autozone.com/fuel-systems/fuel-pump-universal/spectra-premium-electrical-fuel-pump/559614_0_0

That pump makes too much pressure - 100 psi - but I suspect one could be found with 65 psi (as I remember?) needed for this bike?

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    dukedomain

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    Re: Fuel Pump (new idea?)
    « Reply #1 on: Mar 31, 2019, 04:50:01 pm »
    I donít recall anyone using a universal replacement fuel pump.  One reason may be that itís usually the plastic housing that fails, not the pump itself.  Thatís what I recall anyway  :shrug:

    A.T.

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    Re: Fuel Pump (new idea?)
    « Reply #2 on: Mar 31, 2019, 05:00:19 pm »
    I donít recall anyone using a universal replacement fuel pump.  One reason may be that itís usually the plastic housing that fails, not the pump itself.  Thatís what I recall anyway  :shrug:

    The Duke is correct - it's not the pump motor but rather the assembly housing.   

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      Coldfinger

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      Re: Fuel Pump (new idea?)
      « Reply #3 on: Mar 31, 2019, 05:43:57 pm »
      I think th OP means to install the fuel pump ouside of the tank, in the fuel line between the sub-tank and the fuel rail.   

      ElGuapoLoco

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      Re: Fuel Pump (new idea?)
      « Reply #4 on: Apr 01, 2019, 05:06:57 am »
      I think th OP means to install the fuel pump ouside of the tank, in the fuel line between the sub-tank and the fuel rail.

      Yeah.  Why not?

      ElGuapoLoco

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      Re: Fuel Pump (new idea?)
      « Reply #5 on: Apr 03, 2019, 06:09:19 pm »
      bump

      the urban legend

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      Re: Fuel Pump (new idea?)
      « Reply #6 on: Apr 04, 2019, 05:50:18 am »
      You would still need to modify the pump housing,otherwise it would be like trying to drink a milkshake through a cracked straw. The pump would be sucking more air than actual fuel when the fuel level gets low enough.
      I'll stick with my mod. Official testing will begin soon.
      I'd rather die on a motorcycle than live without one.

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      Fasttimez

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      Re: Fuel Pump (new idea?)
      « Reply #7 on: Apr 04, 2019, 06:01:59 am »
      It takes a lot of modification to mount an external fuel pump.  The sub tank needs a custom insert fabbed up for fuel delivery & return.  It would have to have a pressure vessel (like our housing that cracks all the time).  Like Urban mentioned, without some type of way to hold steady pressure when sucking fuel, you'd be sucking air from the fuel sloshing around in the subtank when the level gets low, & just from general cavitation to the pump itself.  Also, you'd need an inline filter element, since our filter is inside of the housing itself & non serviceable.  It would make for easy fuel system testing & maintenance for sure with an externally mounted pump.   

      Phaedrus

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      Re: Fuel Pump (new idea?)
      « Reply #8 on: Apr 04, 2019, 06:14:58 am »
      I'll stick with my mod. Official testing will begin soon.
      :popcorn: :popcorn:

      the urban legend

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      Re: Fuel Pump (new idea?)
      « Reply #9 on: Apr 04, 2019, 07:41:38 pm »
      I'll stick with my mod. Official testing will begin soon.
      :popcorn: :popcorn:

      Sneak peek during fitting and assembly.
      I'd rather die on a motorcycle than live without one.

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      Coldfinger

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      Re: Fuel Pump (new idea?)
      « Reply #10 on: Apr 04, 2019, 08:31:33 pm »
      Ok, first observation after looking at my raider- pretty limited space to work with.  Maybe if the unit will not fit above the sub tank it could be mounted behind one of the covers on either side of cylinder. 

      Next question from someone who is not familiar with fuel pumps - does fuel injection require a special pump vs non-injected?

      Does the pump have to produce the approximate required pressure?  I am guessing it has to produce more pressure and then the pressure is reduced by the fuel regulator. 

      I wonder if the purpose of the plastic housing is to reduce the number of on-off cycles the pump goes thru or if the pump runs all the time. 

      I dont see why an external filter couldnt be plumbed in, like cars have. 

      Assuming the sub tank was still used, the pickup would be near the bottom so I dont see why it would suck any more air than the oem setup - they will both suck air when fuel gets too low. 

      Fuel gauge, totally unsure on that. 

      SilverStar

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      Re: Fuel Pump (new idea?)
      « Reply #11 on: Apr 05, 2019, 04:42:09 am »
      The gauge sending unit is in the main tank so is not an issue for this discussion.

      If I recall correctly this is a non return system.  That means the voltage to the pump varies so the pressure and volume of fuel is controlled by the computer and not by a mechanical regulator.  I know of no external pump designed for this.  They are constant pressure units that require a regulator and return line so you'd have to reengineer the system and tune the computer to make it work.  I lost track of my manual in the move so I need to research it to verify but that's how cars and trucks have been mandated since 1998 or 99.  It's safer in a crash.

      I was wondering if you could trim up a beer can or two and wrap the housing with them for reinforcement.  A couple or three wire zip ties and maybe it would never fail.  Obviously this would have to be done before failure.
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      ElGuapoLoco

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      Re: Fuel Pump (new idea?)
      « Reply #12 on: Apr 05, 2019, 05:15:24 am »
      The gauge sending unit is in the main tank so is not an issue for this discussion.

      If I recall correctly this is a non return system.  That means the voltage to the pump varies so the pressure and volume of fuel is controlled by the computer and not by a mechanical regulator.  I know of no external pump designed for this.  They are constant pressure units that require a regulator and return line so you'd have to reengineer the system and tune the computer to make it work.  I lost track of my manual in the move so I need to research it to verify but that's how cars and trucks have been mandated since 1998 or 99.  It's safer in a crash.

      I was wondering if you could trim up a beer can or two and wrap the housing with them for reinforcement.  A couple or three wire zip ties and maybe it would never fail.  Obviously this would have to be done before failure.

      Normally, fuel injection has a fuel pressure regulator on the fuel rail.  It usually has a vacuum hose attached to it and looks like a vacuum pot.  The mix is varied not only by the duration of the injector opening but by the pressure of the fuel in the rail.

      That may be the old way of doing it - I'm no expert.  I just understand the basics.

      Pleas do look this up.  If it works the way you say then, obviously, my simple idea will not work.

      Meanwhile I'm afraid to take the Raider anywhere because it may quit on me...  I don't think I have seen the price of the reapair parts in a post but it must be a lot.  And having a bike towed home anit cheap, either!

      Here we have a simple bike - no plastic bullshit all over it, blocking everything you need to do to it...  Good looking, good running...  I've been waiting for the other shoe to drop. 

      If I can't depend on it getting home, I guess I will have to sell it :(

      ElGuapoLoco

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      Re: Fuel Pump (new idea?)
      « Reply #13 on: Apr 05, 2019, 05:16:36 am »
      You would still need to modify the pump housing,otherwise it would be like trying to drink a milkshake through a cracked straw. The pump would be sucking more air than actual fuel when the fuel level gets low enough.
      I'll stick with my mod. Official testing will begin soon.

      I'd like to hear about your mod?

      the urban legend

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      Re: Fuel Pump (new idea?)
      « Reply #14 on: Apr 05, 2019, 05:59:13 am »
      The gauge sending unit is in the main tank so is not an issue for this discussion.

      If I recall correctly this is a non return system.  That means the voltage to the pump varies so the pressure and volume of fuel is controlled by the computer and not by a mechanical regulator.  I know of no external pump designed for this.  They are constant pressure units that require a regulator and return line so you'd have to reengineer the system and tune the computer to make it work.  I lost track of my manual in the move so I need to research it to verify but that's how cars and trucks have been mandated since 1998 or 99.  It's safer in a crash.

      I was wondering if you could trim up a beer can or two and wrap the housing with them for reinforcement.  A couple or three wire zip ties and maybe it would never fail.  Obviously this would have to be done before failure.

      The Raider does have a pressure regulator (in left coil cover) and a return line that runs along the lower left side of the tank.


      You would still need to modify the pump housing,otherwise it would be like trying to drink a milkshake through a cracked straw. The pump would be sucking more air than actual fuel when the fuel level gets low enough.
      I'll stick with my mod. Official testing will begin soon.

      I'd like to hear about your mod?

      I actually spent over 30 hours putting together a "how-to" for this mod. I was ready to post it on January 2nd but my new PC crapped out as soon as I saved the final draft. I was unable to open,move,or back up any of my data and lost all of it. I intend to do it again,but I haven't had the heart to start over. Plus I figured getting some actual street time to test it before I post wouldn't be a bad idea.

      Simply put,the only part that gets modified is the pump housing itself. I kept the OEM pump,bypassed the housing (and the internal filter),and added an external fuel filter. The rest of the bike is untouched.

      I'd rather die on a motorcycle than live without one.

      ,,