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Discussion Starter · #1 ·
Here we go..

When you need more fuel you need to look at three critical areas:

  • Injectors
  • Fuel Pressure Regulator
  • Fuel Pump
The first two are addressed by installing larger injectors and a boost referenced fuel pressure regulator (I'm referring to a forced induction application in this regard...).

The fuel pump? Well "I need a bigger fuel pump, so I should just install a Walbro XYZ!", you say? Let's get into it.

The current offerings on the market for intank/submersible fuel pumps range from junk from Autozone up to high end specialty pumps.

The best you can do on a reasonable budge for these bikes is the: Walbro GSS342
You can find this pump (Make SURE it's a real one by buying from a reputable dealer, this is a seriously counterfeited pump due to the popularity) for approximately $100 including filter sock and wire harness.

I'm not going to post the flow rates/data/etc on this pump as it's been beaten to death by myself and many others over the last decade. Google away if you are bored (or interested!).

Quick trick: You can increase the flow (and in my opinion safely) of this pump by using a small nail and a hammer to tamp down the pressure relief valve on the top of the pump. Literally support the pump on a cloth/etc and lightly tap the nail down in the relief hole until it will not return back up. This helps at higher rpms and has been done for years in other enthusiast arenas. It's so popular there was a fairly well known speed shop in the DSM world that was selling "High Flow Walbro" pumps and was exposed for literally doing nothing more than taking stock Walbro pumps and performing this modification.

Mounting:
Next....when you install the Walbro pump (NOTE: I am only referring to the later model Vrod's as I don't have experience with the <2009 models...) you will note that it fits, but requires a bit of Dremel work to the bottom stock mount. Have Dremel will travel....it's easy enough and fits like a glove when done with a bit of trim work.

Clamps and Hose:

Use fuel injection style clamps, NOT Jubilee style! They are not designed for this application nor do you want a leak in-tank. Fuel pressure is what we are after.

For the hose make sure it's fuel submersible 5/16" line SAE 30R10 rated. Tons of places to find it (even your local auto parts store, but you will pay more). You need less than a foot for this job.

WIRING:

Inside the tank:
So now we really get into the weeds. The stock wiring IS NOT acceptable for this pump. Period, end of story. It's 16 gauge CCA (look up CCA wire to understand why I use that acronym like a 4 letter word) inside the tank.

Wire to use: PTFE/Teflon covered 14 gauge wire. You will not find this at Home Depot or likely an autoparts store. Yes it's expensive, however it IS what you should be using (it's fuel submersible rated/won't turn into slimy gunk that ruins your pump and ultimately injectors). I recommend Ebay. There are several military surplus suppliers that sell this spec of wire (even pure silver which is overkill but cool!) for pennies on the dollar. I bought 2 spools for other projects which should be a lifetime supply. Make your life easy, get red and black.

So, you have the wire. Now it's time to look at the terminals and connecting blocks inside the tank. You have a 2 wire block at the fuel pump itself/the one that comes with the pump and a red and black wire. This wire is OK, but not ideal. What you want are 2 continuous runs of red/black wires all the way up to the connector block right under the lid of the pump assembly.

For the fuel pump block itself, use a small jewelers style flat head screw driver to release the two wire terminals. In my attached pictures, the terminals you want to use are the ones that are brass colored female spade style connectors. I hunted via Google images to find a similar style and scored.

Note on terminals: You will want/need a Metripack/Weatherpack (oh did I forget to mention Harley loves GM for electronics and terminals!?) style crimper. The one I bought is very cheap (requires two operations versus the higher end spring loaded/single operation for seal and crimp).

Now you have your nice appropriate sized and correctly sheathed 14 gauge wire directly attached to your fuel pump electrical connector. Let's move up the chain....

The next stop is the blue colored connection block right under lid. Using those handy jewelers screw drivers disassemble the wire lock and carefully insert in the release holes below each pin hole so you can remove the wires.

Once again....now we see that we need another style Metripack wire terminal: Metripack 280 series

Use the handy tool I show in the pictures to crimp these terminals. Reinsert and reinstall the wire lock.

NOTE: You have one purple ground wire left in the assembly. You can reuse that as it's a ground for the spring assembly and nothing more. Yes I soldered that (see picture) without using heatshrink. No need to cover a submersed ground wire.

Quick note: The fuel return hose (the oem yellow/brown stained plastic hose) can be moved to the outside of the fuel level sender to prevent fuel from returning and pouring right onto the pump sock. Highly recommended and takes 2 seconds to move while this assembly is outside the tank.

Now you can reassemble your fuel pump assembly (you DID buy a new large o-ring from the dealer that fits under the tank flange/lid right? If not, stop..do it....almost always they are stretched out after you pull the assembly out....AND use fuel resistant sealant on the new gasket, not inappropriate blue RTV. I use "Motoseal" from Permatex.).

At this point you have the fuel pump mounted, correct fuel submersible rated hose, correct clamps, continuous 14 gauge/teflon covered wire, all connected via the fuel pump terminal block and the oem under lid assembly terminal block. No heat shrink needed, no junk crimps, just nice appropriately sized wire (WHY do I keep hinting at wire size? If you lookup the max amp draw of the GSS342 you quickly realize that you are exceeding the oem wire size/type AND possibly the shared circuit for the oem pump, more on that in a second).

Outside the tank:

"Wait, I upgraded the wire inside the tank so that is good enough right?". NO. Not just no, hell no.

Once again, you went through all this trouble so far (and you can thank me with a calorie free beer if that existed) to get the appropriate connectors/wire/tools to install the assembly intank correctly. It's not much more effort (and totally needed) to upgrade the wire externally AND give your new shiny fuel pump it's own dedicated circuit. Here goes:

On TOP of the tank assembly you will find two connectors. One is for the fuel level sender (obvious which one it is) and the other is the power connector for the fuel pump itself.

Grab that screw driver. Disassemble the fuel pump power block.

Now, once again we find more of our friend Mr. Metripack....BUT this time not so easy to find (I could not identify exactly which terminals they are from the Metripack catalog so I cheated...). I "cheated" by pulling wiring parts diagrams on Ronnie's HD (great site!). Did you know that Harley is so proud of their parts they even assign part numbers down to the wire terminals AND the seals? YEP!

So, you want these:

(Quantity: 2) 72494-07 <--These are the terminal rubber seals that you need to properly reinstall the new wire.
(Quantity: 2) 72493-07 <--The elusive Metripack style wire terminals used in the power connector that doesn't quite m
Electronics Hardware programmer Technology Electrical connector Electronic component
Wire Auto part Electrical wiring Vehicle
Soil
Auto part Vehicle Metal
Wire Cable Electronic device Technology Electrical connector
atch anything I can find on the aftermarket. NOTE: BUY 3 of these, you will likely screw the first one up when you learn how to crimp these. Couple that with the fact dealers stock NONE of this stuff you will thank me when you wait a week or two and trash the first one and smile that you have two more left.

14 gauge copper (NOT CCA) wire is what you want. Teflon/PTFE need not apply here as you are not inside a fuel laden environment now. Buy a nice couple spools of red and black.

So....at this point you may be wondering "Can't I just upgrade the wiring to 14 gauge wire back to the stock fuse?". Yes, but you shouldn't. It's a shared circuit! Let's finish the job right......

Next up, get a 12 volt Bosch automotive style relay (a million copies available on Ebay/etc).

NOTE: Not all relays are equal. Look for one that has a nice wire terminal block with 14 gauge or bigger (NOTE: American wire gauge (AWG), if you don't know, goes bigger the smaller the # is.) wire.

What you want to do is wire the relay as follows:

  • Terminal 86: Connect to the original switched 12 volt + wire in the fuel pump circuit (use a multimeter to verify or consult your shop manual, I don't recall the wire colors off hand).
  • Terminal 85: Ground
  • Terminal 30: Connect your new 14 gauge stranded copper wire (once again, NOT CCA) to this terminal. This wire will go straight to the positive post on your battery....WITH an inline waterproof fuse/holder (millions of these on Ebay/Amazon as well, once again make sure the one you choose has nice large gauge wire and a 30 amp fuse). See picture below for reference.
  • Terminal 87: Connect to the positive terminal on the outside tank power connector that goes to the fuel pump +.
I mounted the relay under the passenger seat frame lip. If you can't tell I'm a big fan of split loom Techflex wire management loom. Super easy to use and you can secure it with your bucket of zip ties when done.

NOTE ON GROUND WIRE: For the ground wire on the outside tank power connector, connect that to a nice ground (or to the battery - directly if desired) with your new 14 gauge wire as well.

Net effect: When you turn the bike ignition switch to on/kill switch to run you should hear the relay click and power should now be delivered to the fuel pump resulting in the priming noise you are used to. No click or no priming sound? You messed up the wiring. Also, while I like nice tools, you can certainly pickup a $5 Harbor Freight digital multimeter to verify your wiring and continuity. If you do lots of wiring (house, cars, bikes, outlets, etc) I recommend investing in one of the many nice Fluke meters....but that's not needed for this simple job.

So there it is. From fuel pump to battery, you are now on a dedicated and properly wire sized circuit (including properly sized fuse!). You will have the maximum current flow possible to your pump and as a result benefit from max flow.

Now...go get your parts.

Side note: If you don't have a solder gun, get one. I dabble in electronics, but I can't say enough how nice it is to have a nice solder station. I love the Hakko FX888D. You can find them for a bargain if you hunt. Nothing like watching a solder station heat up in 20 seconds to your exact set point. Also, heat shrink is a must for external wiring. DO NOT use a freaking lighter to shrink it please! Use a heat gun (yes the same one you use to strip paint/peel linoleum) is the best and safest way.
 

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Discussion Starter · #6 ·
Do you have a schematic for the pump circuit your proposing?
No I don't, however the only real change to the wiring (outside the tank that is) is using the +12v wire to trigger the relay on (and of course have a constant +12v wire from the battery connecting from the relay to the pump when triggered).

Look at my comments about the Bosch relay. It should make sense. There are also a ton of examples on the web about using a relay to isolate circuits/run power from the battery to a fuel pump. Common stuff in the car world.

And for anyone reading this, I guarantee you are going to have more consistent fuel pressure going this route. The stock wiring and circuit is NOT sufficient for this monster of a fuel pump (and monster is right, I run 2 of these in parallel on a 900 horsepower drag car feeding 4 2100cc fuel injectors....ONE of these is enough to support 600 horsepower...so yes, this will end the fuel pump dilemma if you have one on these bikes).
 

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Yea there's some pretty enlightening data online about the amp draw of these pumps. I've heard the name walbro but never had the need to replace a fuel pump untill now.

As far as the wiring description, I read it, but my biggest mis understanding was the terminal numbers as I'm trying to apply this to an 06 R.

That being said I remembered many, many moons ago I was considering swapping in a 2013 muscle motor, so i purchased an electrical diagnostics manual to cross reference and make sure I could adapt it to my R. I just looked and kept that manual so I can cross reference the terminals you specify and make sure they're the same on the R. If they're not it's a little more homework but easy enough to do.

I've added isolated circuits before but always have a wiring diagram to reference before I cut wire. I figured it couldn't hurt to see if you had one handy.
 

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Here we go..

When you need more fuel you need to look at three critical areas:

  • Injectors
  • Fuel Pressure Regulator
  • Fuel Pump
The first two are addressed by installing larger injectors and a boost referenced fuel pressure regulator (I'm referring to a forced induction application in this regard...).

The fuel pump? Well "I need a bigger fuel pump, so I should just install a Walbro XYZ!", you say? Let's get into it.

The current offerings on the market for intank/submersible fuel pumps range from junk from Autozone up to high end specialty pumps.

The best you can do on a reasonable budge for these bikes is the: Walbro GSS342
You can find this pump (Make SURE it's a real one by buying from a reputable dealer, this is a seriously counterfeited pump due to the popularity) for approximately $100 including filter sock and wire harness.

I'm not going to post the flow rates/data/etc on this pump as it's been beaten to death by myself and many others over the last decade. Google away if you are bored (or interested!).

Quick trick: You can increase the flow (and in my opinion safely) of this pump by using a small nail and a hammer to tamp down the pressure relief valve on the top of the pump. Literally support the pump on a cloth/etc and lightly tap the nail down in the relief hole until it will not return back up. This helps at higher rpms and has been done for years in other enthusiast arenas. It's so popular there was a fairly well known speed shop in the DSM world that was selling "High Flow Walbro" pumps and was exposed for literally doing nothing more than taking stock Walbro pumps and performing this modification.

Mounting:
Next....when you install the Walbro pump (NOTE: I am only referring to the later model Vrod's as I don't have experience with the <2009 models...) you will note that it fits, but requires a bit of Dremel work to the bottom stock mount. Have Dremel will travel....it's easy enough and fits like a glove when done with a bit of trim work.

Clamps and Hose:

Use fuel injection style clamps, NOT Jubilee style! They are not designed for this application nor do you want a leak in-tank. Fuel pressure is what we are after.

For the hose make sure it's fuel submersible 5/16" line SAE 30R10 rated. Tons of places to find it (even your local auto parts store, but you will pay more). You need less than a foot for this job.

WIRING:

Inside the tank:
So now we really get into the weeds. The stock wiring IS NOT acceptable for this pump. Period, end of story. It's 16 gauge CCA (look up CCA wire to understand why I use that acronym like a 4 letter word) inside the tank.

Wire to use: PTFE/Teflon covered 14 gauge wire. You will not find this at Home Depot or likely an autoparts store. Yes it's expensive, however it IS what you should be using (it's fuel submersible rated/won't turn into slimy gunk that ruins your pump and ultimately injectors). I recommend Ebay. There are several military surplus suppliers that sell this spec of wire (even pure silver which is overkill but cool!) for pennies on the dollar. I bought 2 spools for other projects which should be a lifetime supply. Make your life easy, get red and black.

So, you have the wire. Now it's time to look at the terminals and connecting blocks inside the tank. You have a 2 wire block at the fuel pump itself/the one that comes with the pump and a red and black wire. This wire is OK, but not ideal. What you want are 2 continuous runs of red/black wires all the way up to the connector block right under the lid of the pump assembly.

For the fuel pump block itself, use a small jewelers style flat head screw driver to release the two wire terminals. In my attached pictures, the terminals you want to use are the ones that are brass colored female spade style connectors. I hunted via Google images to find a similar style and scored.

Note on terminals: You will want/need a Metripack/Weatherpack (oh did I forget to mention Harley loves GM for electronics and terminals!?) style crimper. The one I bought is very cheap (requires two operations versus the higher end spring loaded/single operation for seal and crimp).

Now you have your nice appropriate sized and correctly sheathed 14 gauge wire directly attached to your fuel pump electrical connector. Let's move up the chain....

The next stop is the blue colored connection block right under lid. Using those handy jewelers screw drivers disassemble the wire lock and carefully insert in the release holes below each pin hole so you can remove the wires.

Once again....now we see that we need another style Metripack wire terminal: Metripack 280 series

Use the handy tool I show in the pictures to crimp these terminals. Reinsert and reinstall the wire lock.

NOTE: You have one purple ground wire left in the assembly. You can reuse that as it's a ground for the spring assembly and nothing more. Yes I soldered that (see picture) without using heatshrink. No need to cover a submersed ground wire.

Quick note: The fuel return hose (the oem yellow/brown stained plastic hose) can be moved to the outside of the fuel level sender to prevent fuel from returning and pouring right onto the pump sock. Highly recommended and takes 2 seconds to move while this assembly is outside the tank.

Now you can reassemble your fuel pump assembly (you DID buy a new large o-ring from the dealer that fits under the tank flange/lid right? If not, stop..do it....almost always they are stretched out after you pull the assembly out....AND use fuel resistant sealant on the new gasket, not inappropriate blue RTV. I use "Motoseal" from Permatex.).

At this point you have the fuel pump mounted, correct fuel submersible rated hose, correct clamps, continuous 14 gauge/teflon covered wire, all connected via the fuel pump terminal block and the oem under lid assembly terminal block. No heat shrink needed, no junk crimps, just nice appropriately sized wire (WHY do I keep hinting at wire size? If you lookup the max amp draw of the GSS342 you quickly realize that you are exceeding the oem wire size/type AND possibly the shared circuit for the oem pump, more on that in a second).

Outside the tank:

"Wait, I upgraded the wire inside the tank so that is good enough right?". NO. Not just no, hell no.

Once again, you went through all this trouble so far (and you can thank me with a calorie free beer if that existed) to get the appropriate connectors/wire/tools to install the assembly intank correctly. It's not much more effort (and totally needed) to upgrade the wire externally AND give your new shiny fuel pump it's own dedicated circuit. Here goes:

On TOP of the tank assembly you will find two connectors. One is for the fuel level sender (obvious which one it is) and the other is the power connector for the fuel pump itself.

Grab that screw driver. Disassemble the fuel pump power block.

Now, once again we find more of our friend Mr. Metripack....BUT this time not so easy to find (I could not identify exactly which terminals they are from the Metripack catalog so I cheated...). I "cheated" by pulling wiring parts diagrams on Ronnie's HD (great site!). Did you know that Harley is so proud of their parts they even assign part numbers down to the wire terminals AND the seals? YEP!

So, you want these:

(Quantity: 2) 72494-07 <--These are the terminal rubber seals that you need to properly reinstall the new wire.
(Quantity: 2) 72493-07 <--The elusive Metripack style wire terminals used in the power connector that doesn't quite m View attachment 605063 View attachment 605064 View attachment 605065 View attachment 605066 View attachment 605067 atch anything I can find on the aftermarket. NOTE: BUY 3 of these, you will likely screw the first one up when you learn how to crimp these. Couple that with the fact dealers stock NONE of this stuff you will thank me when you wait a week or two and trash the first one and smile that you have two more left.

14 gauge copper (NOT CCA) wire is what you want. Teflon/PTFE need not apply here as you are not inside a fuel laden environment now. Buy a nice couple spools of red and black.

So....at this point you may be wondering "Can't I just upgrade the wiring to 14 gauge wire back to the stock fuse?". Yes, but you shouldn't. It's a shared circuit! Let's finish the job right......

Next up, get a 12 volt Bosch automotive style relay (a million copies available on Ebay/etc).

NOTE: Not all relays are equal. Look for one that has a nice wire terminal block with 14 gauge or bigger (NOTE: American wire gauge (AWG), if you don't know, goes bigger the smaller the # is.) wire.

What you want to do is wire the relay as follows:

  • Terminal 86: Connect to the original switched 12 volt + wire in the fuel pump circuit (use a multimeter to verify or consult your shop manual, I don't recall the wire colors off hand).
  • Terminal 85: Ground
  • Terminal 30: Connect your new 14 gauge stranded copper wire (once again, NOT CCA) to this terminal. This wire will go straight to the positive post on your battery....WITH an inline waterproof fuse/holder (millions of these on Ebay/Amazon as well, once again make sure the one you choose has nice large gauge wire and a 30 amp fuse). See picture below for reference.
  • Terminal 87: Connect to the positive terminal on the outside tank power connector that goes to the fuel pump +.
I mounted the relay under the passenger seat frame lip. If you can't tell I'm a big fan of split loom Techflex wire management loom. Super easy to use and you can secure it with your bucket of zip ties when done.

NOTE ON GROUND WIRE: For the ground wire on the outside tank power connector, connect that to a nice ground (or to the battery - directly if desired) with your new 14 gauge wire as well.

Net effect: When you turn the bike ignition switch to on/kill switch to run you should hear the relay click and power should now be delivered to the fuel pump resulting in the priming noise you are used to. No click or no priming sound? You messed up the wiring. Also, while I like nice tools, you can certainly pickup a $5 Harbor Freight digital multimeter to verify your wiring and continuity. If you do lots of wiring (house, cars, bikes, outlets, etc) I recommend investing in one of the many nice Fluke meters....but that's not needed for this simple job.

So there it is. From fuel pump to battery, you are now on a dedicated and properly wire sized circuit (including properly sized fuse!). You will have the maximum current flow possible to your pump and as a result benefit from max flow.

Now...go get your parts.

Side note: If you don't have a solder gun, get one. I dabble in electronics, but I can't say enough how nice it is to have a nice solder station. I love the Hakko FX888D. You can find them for a bargain if you hunt. Nothing like watching a solder station heat up in 20 seconds to your exact set point. Also, heat shrink is a must for external wiring. DO NOT use a freaking lighter to shrink it please! Use a heat gun (yes the same one you use to strip paint/peel linoleum) is the best and safest way.
Don’t crimp wires soldering them would be way better than crimping them not hard then use heat shrink on them as they’ll never come apart or short out this way
 

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Don’t crimp wires soldering them would be way better than crimping them not hard then use heat shrink on them as they’ll never come apart or short out this way
Sorry your wrong: Crimp and use the proper crimping tool and crimp size.

Metripack, deutschs, AMP terminal require a crimp and a very specific one at that as the terminals relies on deformation of the wire to create a uniform size to fit the housing.

Additional there's a specific length of exposed copper that is needed as the crimp is 2 fold, one to sandwich the copper between the tin wings of the terminal, for signal continuity and the second is a wire lock that bends prongs into the wire insulation for support.

Soldering melts the insulation removing that physical lock and is much more susceptive to temperature cycling cracking making it much less secure, whereas a mechanical crimp is immune to this.

Solder has its place but not for this.
 

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Discussion Starter · #10 ·
Sorry your wrong: Crimp and use the proper crimping tool and crimp size.

Metripack, deutschs, AMP terminal require a crimp and a very specific one at that as the terminals relies on deformation of the wire to create a uniform size to fit the housing.

Additional there's a specific length of exposed copper that is needed as the crimp is 2 fold, one to sandwich the copper between the tin wings of the terminal, for signal continuity and the second is a wire lock that bends prongs into the wire insulation for support.

Soldering melts the insulation removing that physical lock and is much more susceptive to temperature cycling cracking making it much less secure, whereas a mechanical crimp is immune to this.

Solder has its place but not for this.
100%. It's common myth that solder = better than proper crimp ("PROPER" being the optimal word).

Now, with that being said, I often solder wires where vibration/rub scenarios aren't present with no issues (small electronics, portions of car audio installs, etc).

If people don't believe this go look up milspecs (or NASA references) on crimping. If it's good enough for battle it's good enough for your vehicle!
 
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