Fuel Pump Repair - Yes You Can

[hammer]

Is your fuel pump singing to you? Maybe the bike is just not running right? Some bikes are actually bogging down under throttle. Could be bad gas or your fuel pump dying. Like mine, it could be the fuel strainer in the fuel pump assembly is covered in crap. That is not surprising after 75,000K or 50,000 miles.


Kawasaki says the fuel pump is not serviceable and must be replaced. Do that if you want NO risk but check out the cost of a new Kawasaki fuel pump "assembly". If you add shop labor to the mix you could be facing $1,000 or more depending on where you live. IMHO, I think this is just crap engineering and design on Kawasaki's part. Just like their steering stem bearing design. Anyway, rants would not fix my problem, so I set out to disprove the pump can't be serviced. I did this at my own risk and you will too if you decide to go that way.


Start with removing the fuel tank. There are instructions for that so do the search and use your manual that is available on the site here. My tips include, disconnect the negative battery post before doing anything and drain the fuel tank. You can get an inexpensive fuel transfer pump from Harbour Freight. Remove the speedo display assembly and flip the tank onto a towel covered bench or table. Note the orientation of the pump outlet and remove the 5 bolts. Carefully lift out the pump assembly and save the large O-ring. You can check inside the tank for condition then cover the hole. Mine had no visible rust.

Here are the steps to disassembly. Once you see the pump assembly on the bench it will all make sense, I hope. Take pictures so you have a guide in case memory fails you on what goes where. Yes use vinyl gloves to protect your hands and you grip things better so you don't lose important bits. A vinyl glove also fits nicely over the hole.

Unbolt the 7mm bolts holding the 2 primary wiring connectors noting the wire color positions and the nut, split washer sequence. Unscrew the clips from the 2 pump housing rails. One side also holds the additional black wire. Using the edge of a table, bench or whatever "pull straight back" to separate the pump assembly from the housing. The grommet seal inside will offer resistance but a steady pull does it. Once out of the tank and gas the air starts to dry rubber parts out quickly so I lubed the grommet and other rubber parts with a little Vaseline. It also makes re-assembly easier.


Remove the fuel strainer. This means simply unclip the white plastic holder on the end, remove the black rubber piece and twist and pull to remove the strainer. You can try back flushing the strainer with gas or air but I don't recommend that as varnish alone will degrade the strainer over time. You would not backflush your oil filter would you? I sourced the fuel strainer here, http://www.highflowfuel.com/i-14389244-new-intank-efi-fuel-pump-strainer-only-suzuki-boulevard-c90-c90t-black-edition-vl1500-vl1500t-vl1500b-2005-2009.html. $10.50 delivered and it is the exact same. Leave the white plastic guard that comes with the replacement. It also helps when you push the strainer down into place.


Now reassemble by pushing the assembly back into place if you are not replacing the pump. Your investment so far is your time and $10.50 for the strainer. When pushing the assembly back in lube the grommet as suggested and look at the shadow of the grommet from outside the housing to make sure it has seated properly. Re-connect the wires and clips in reverse order. Do not over tighten the 2 primary wire connectors. I tested the pump "briefly" using my spare Nomad bench battery. Obviously clip the right - and + wires. The black should be negative. This was just to ensure the connectors were done properly and the pump "fired".

Re-install the assembly in the tank using blue loctite on the bolts. Do NOT overtighten and use a cross pattern tightening sequence like mounting a car rim. The manual says 87 in lbs which is 7.25 foot lbs so not that tight. It's the large rubber o Ring that does the work here. Reinstall the tank, add gas, check for any leaks, start it up, check for leaks, go ride.

If you need to/want to replace the pump you can source it from, http://www.highflowfuel.com/ag-81070.83649.133428.83568-2006-kawasaki-vulcan-1600-vn1600-vn-1600-vn1600d-mean-streak-efi.html. The model#HFP-382K comes with the HFP-SUZS1 fuel strainer for $70. They actually return your phone calls and are good with questions. I know the fuel strainer is exactly right and the pump should be too. Cheap insurance in my book. I had a used pump with new strainer and it is working perfectly. After having the original pump whistling that long I opted to replace it. I will order the new HighFlow pump this winter and will then have a completely re-furbished pump assembly as spare or for sale and will report so the option can be counted on by others.

To replace the pump requires this added step, hold the pump body and separate the pump by pushing it off with your thumbs. Remove the pump and transfer the wiring clip to the new High Flow pump. Check the grommet in the orifice. Dry it out some and check to make sure it is not dried out, cracked or split. Late Edit: The rubber grommet shown in the assembly pic IS a Mitsubishi part#MR431121. My reference was a Mitsubishi Lancer EVO but the grommet is used in too many vehicles to list here and can be found in a search on MOPAR. I got mine at a local Mitsubishi dealer in Canada for $4 and here is just one listing in $US,
http://www.streettunedmotorsports.co...nk_grommet.htm




Fuel pump components


Re-assemble as before.
Idaho had a pump where the grommet was split. He jury rigged a solution using a different pump and rubber hose. It was creative but I am trying to source a replacement and will update if I find it. This is just a pressure fit. No clamps or hoses should be required.


If you are using rubber fuel line instead of the grommet, do not use standard heater or vacuum hose. SAE30R9 spec hose resists sour gas and ethanol. SAE30R10 resists immersion in gas like the in-tank install on our bikes. It should be 5/16" x 9/16" but Idaho hopefully will tell us what hose he used. Your local auto supplier should be able to supply it.A little Vaseline on the male end will help the new pump slide right in.
This is DIY so all your creative updates or suggestions would be appreciated.

[duffy]

Excellent write up Hammer............do you think it will be the same for the 1500?

[hammer]

Plug in the year, make, choose 1500 Classic and choose EFI if it is and then click SHOP.

[hammer]

Finally got the pics to work. I hope this will help those that have had problems with their fuel pump. There should be no reason to buy Kawasaki's hugely overpriced pump assembly. At the very least the fuel strainer, rubber grommets/bushings and the wire harness should be component parts offered as replacement parts. I don't really see how this is different from other components like the final drive parts.

Hopefully someone who can, will discuss this with Kawasaki.

[hammer]

After some research, this may be the missing part, http://www.extremepsi.com/store/prod...roductid=25830
I can't tell the size but most inlets are similar sized. This is an OEM Misubishi Lancer EVO Fuel pump grommet. Hey Idaho, you may want to try this out in case your hose mod causes you any grief. Then you can tell us all if it fits our Mitsubishi pump housing. Did you keep the torn original?

From what I have read, this part alone causes issues like tearing resulting from octane boosters and ethanol in the gas.

[BigRed]

Great write-up. Thanks!

[ringadingh]

Very good writeup, I'll get it put in the tech section.

[cnc]

Good info Hammer, so I am taking it that from the listing for the new screen, Suzuki is using the same pump / screen setup in some of their bikes.

[hammer]

Yes and I am sure quite a few others too. Mitsubishi and Denso are both large suppliers in automotive and motorcycle fuel pump applications across the board, including Harley. I came across a Denso pump used in 785 different vehicles both import and domestic.

The trick was to find a small fuel strainer that would fit our pump but, more important, the small pump housing used. That alone should solve most of the issues for us. It was a bonus to find the fuel strainer and the pump. I am closing in on replacement rubber grommets now. With that, a complete refurb of the pump could be done for less than $100.

[VulcanE]

Great write-up Hammer, I am bookmarking this, cause I noticed the other day when I turned my switch on, the fuel pump didn't sound like it usually does as it primes. After that one time it sounded normal, but it got me to thinking/worrying about our suspect fuel pumps.

[Idaho]

Originally Posted by hammer

After some research, this may be the missing part, http://www.extremepsi.com/store/prod...roductid=25830
I can't tell the size but most inlets are similar sized. This is an OEM Misubishi Lancer EVO Fuel pump grommet. Hey Idaho, you may want to try this out in case your hose mod causes you any grief. Then you can tell us all if it fits our Mitsubishi pump housing. Did you keep the torn original?

From what I have read, this part alone causes issues like tearing resulting from octane boosters and ethanol in the gas.

Yep, I kept the original. The Mitsubishi grommet looks similar except in the pic the hole looks too big. They are cheap enough so I think it would be worth it to get one for comparison. Thanks,

[hammer]

Thanks Idaho. Yup you are right, size matters

I used a digital caliper and measured the OEM grommet I have here:
I.D. 8.83mm or .347" probably commonly 5/16"
O.D 16.8mm or .662" - commonly 7/16"
Length 14.7mm or .579" - commonly 9/16"

I checked some parts specs that give ranges on both sides of those dimensions so if you can get that info. from your end we may be in business.

I am expecting a call from a Mitsubishi dealer here who will get us a measurement. I also talked to a tech who does work on the Mitsubishi, Suzuki and BMW and thinks this should be pretty standard size used in a lot of pumps.

He prefers the grommets to hoses because they are more pliable and probably seal better. BUT, he also believes these grommet and seal tears are showing up more due to ethanol.

He also recommends using #331 Kleen Flow Caliper Slide Grease or Liqid Teflon PTFE, Permatex has that but I have never used it for fuel line applications.

I have stored rubber fuel line parts after spraying with a light oil and used oil like Vaseline to lube components to ease connections. That's probably old school and maybe others have more up to date knowledge on that.

[Eagle Eye]

Great job as usual Hammer. Eventually they all get there so thanks for the info.

[hammer]

Hey thanks. See you in Chewelah. Not long now and really actual riding is much more important. Just don't touch my PBR.

[Idaho]

The last time I re-worked the hose in the fuel pump besides cutting a slightly longer chunk of hose to get a better seal I also bought a flat spring steel hose clamp and put it around the hose right on top of the pump housing. Don't know if the clamp or the longer piece of hose is what made the diff but the bike is sure running better now that it did for 4300 miles to Ohio and Arkansas and back.