Article [11] ST1100 - Fuel Pump Replacement

Yes, the aux pump is magnetic. Haven't hacked one open tho.

The STock pump is an electric motor with an impeller on the end of the shaft, sucking/pushing fuel thru a screen and a hose and on out to the carbs. Don't know how it "regulates" except for the pressure of the float valves against their stops. If the pressure is TOO HIGH, would expect it's pretty easy to overcome those needles and provide a rich mix. In that case, the faster ya go, the better it should run. :D

I'm still not sure of the function of the "big" hose and internal tank tube.
 
Air will pass through them without much effort. I would have to think it is a moot point.
 
George said:
I'm still not sure of the function of the "big" hose and internal tank tube.
Click to expand...


Looking at Service Manual page 21-7, diagram shows the large hose to be (4) Fuel inlet tube.

So, presumably, sucking on the end of that in-tank tube should draw fuel.

Next question, why is there a "sock" around the tail end of the pump assembly if fuel is not drawn in there? I'm continuing to look at STuff.

Side Note: test procedure for the pump sez to "remove the instrument panel" to get to the back of the fuel cut-off relay and disconnect it, then jump between the black and red/brown wires to power the pump with the ignition on. Sure seems a lot simpler to just run a 12V wire from the battery or wherever stright to the pump. When is the last time ya removed yur instrument panel!? :22yikes: :D

Recommended flow is 640cc/min. I think I'll test all three pumps I have on hand (4, if I do lipSTick as well) for comparison purposes.

Oh, and it sez to flow for 5 seconds and multiple the result by 12. Easier to test for 6 seconds and multiply by 10. Decimal, don't'cha know. :D (Short duratin test probably to avoid overheating the pump?)
 
Well, I stepped in it and it's gonna coST me. (Not really, but...) Called Hi-Flow in LA this morning. Chris said he'd cancel the first order (2 pumps). Waited 'til the cancel notice came thru, accepted it, went to pay for the single pump and...

...they'd canceled the single pump and left the order for two. So I just bought'em both. Someone else is gonna need one soon. :D
 
George said:
I screwed up my order and now have THREE of these awaiting payment. Sent'em a note and gonna call in a few to get it straightened out. :D
Click to expand...

George, the way you ride all around the country you should have three fuel pumps!! :D

:usflag1:
 
George said:
Side Note: test procedure for the pump sez to "remove the instrument panel" to get to the back of the fuel cut-off relay and disconnect it, then jump between the black and red/brown wires to power the pump with the ignition on. Sure seems a lot simpler to just run a 12V wire from the battery or wherever stright to the pump. When is the last time ya removed yur instrument panel!? :22yikes: :D
Click to expand...

Well Maw Honda knows how we like to tinker with our bikes. The advantage of doing that I would imagine is that it verifies that the relay isn't the issue. It also tests all the wiring without having to do that later. If the pump later tests out fine.

There are lots of things that Honda calls for in the SM that we know faster ways of doing. So it doesn't shock me that much.
 
<edit, name change> [-]Mark[/-]Sennister, if ya turn on the ignition and the pump starts, then stops, the relay and wiring are all working correctly. Then start the engine and the pump starts again, all is good. :D (The Darth helmet threw me off. All youse Dark Siders look alike. :duck: :D)
 
George said:
<edit, name change> [-]Mark[/-]Sennister, if ya turn on the ignition and the pump starts, then stops, the relay and wiring are all working correctly. Then start the engine and the pump starts again, all is good. :D (The Darth helmet threw me off. All youse Dark Siders look alike. :duck: :D)
Click to expand...

True but it depends on what they are testing for. If it is a total failure, the pump just doesn't come on, then I get bypassing the relay. Personally I would start like you said and hook the fuel pump up direct first (with a fuse) before messing with pulling the instrument cluster.

In our case I think we more often experience more of an intermittent failure where the pump just can't keep up. Then you are right, the test in the manual wouldn't really help.
 
Weirdest thing for me, the "old" pump is now working again with no apparent loss of torque. Headed out there now (gotta "make" an appropriate graduated beaker as Deba won't let me take any of her stuff to the garage... :D) to test several pumps for actual output capacity.
 
George said:
Weirdest thing for me, the "old" pump is now working again with no apparent loss of torque. Headed out there now (gotta "make" an appropriate graduated beaker as Deba won't let me take any of her stuff to the garage... :D) to test several pumps for actual output capacity.
Click to expand...

Yeah, I saw where you replaced that hose in the tank. Maybe that was the issue.
 
Here is the link again to the original fuel pump pdf that started this all. From what I understand when I looked at this a couple of years ago, the GL1500 and the ST100 use the same exact fuel pump assembly

http://www.berrysweb.com/Documents/GL1500_FuelPump.pdf

He recommends using the airtex E8371 which can be found just about anywhere (amazon $48, advanced auto $55, etc)and that is what I was considering using


I also looked up a fuel pump for a 1974 vega that I though would work (The ST probably has more horsepower than it does) - the PERFORMANCE ELECTRIC P06K. They sell for less than $26 (check rock auto)

airtex pump on the left, ebay pump in the middle, $26 performance electric fuel pump for a 1974 chevrolet vega on the right (geez it looks like the $80 ebay pump...)

Link to Rock Auto Performance electric pump > http://www.rockauto.com/catalog/moreinfo.php?pk=1400485

edit - I took a closer look at the ebay pump and they do list it as the recommended airtex E8371 although it sure looks like the Performance Electric from the picture
 

Attachments

  • airtex.jpg
    airtex.jpg
    180.7 KB · Views: 16
  • ebay.jpg
    ebay.jpg
    36.7 KB · Views: 22
  • vega fuel pump.jpg
    vega fuel pump.jpg
    22.7 KB · Views: 24
I went back and re-read the PDF for the Goldwing 1500 pump replacement and found the answer to my question about what happens to the vent tube now that the aftermarket replacement pump doesn't have anywhere to hook it up:

"So what about the other hose that connects to the fitting just inside the tank opening??? Well, it is just a breather tube and is not needed with the new pump. This is not just from me but from others who have gone down this path before and the second hose* is simply not an issue. The only thing that might be an issue is slightly reduced fuel capacity before you run dry. If you are someone who regularly takes it down to "fumes", then those "fumes" might come a a few miles sooner but it is not going to be much different. I suppose if you just HAVE to know, then run the pump dry and see how much fuel is left."
 
I gotta take some pics.

On the stock pump, that "fuel inlet hose" connects to a fitting on the tail end of the pump, next to the output hose. With the motor out of it's housing, you can see the other side of the fitting dumps into the fuel pickup area (the area covered by the fine mesh filter. That area is open to the pump impeller and is where fuel is picked up and forced thru the output hose of the pump.

I still fail to see the "fuel input" function of the larger hose. When fuel level drops down to the lower level of the the impeller opening, yur out'a gas. (I also still wanna know where the "other end" of the in-tank tube goes.)

The white 90? elbow connects the 1/2" "fuel input" hose. The open area here is what is supposed to be covered with the fine mesh screen, it was torn on this pump first time I took it out at Mt. Calm, TX.
IMG_6509 (899x1200).jpg

The other end of that fitting is here (the white ring). This is looking down into the area where the 'lectric motor fits.
IMG_6510 (900x1200).jpg

This is my "auxilary" facet pump, I'm gonna leave it in place, with a switch in the power wire, just in case.
IMG_6511 (1200x900).jpg

Anyway, good news is the pump out'a STanley (nee ReSTored) is now in place. It didn't run when I first tried it, but a little lube and exercise got it working well. The flow is much higher than required. Assume standing in stale gas for over 2 years didn't help.

The other good news is, I didn't burn the house down. (The term STupid applies here.)

READ this warning (it appears twice on these pages.) Note where it sez "or Sparks". Maybe that's why they want ya to use a jumper on the fuel cut-off relay and the ignition switch to test the pump.
IMG_6512 (1200x900).jpg

...Or this might happen!!!!
IMG_6513 (1200x900).jpg

And remember, in any case, to keep one of these handy.
IMG_6514 (872x1200).jpg

Only significant damage was to the service manual, and the (plaSTic bucket into which I was pumping the gas! <serious head slap> :doh1:) Got a couple blisters on the heal of my left hand (2nd degree burn) and a big black splotch out on the drive way where I pushed the bucke with the service manual.

It was much closer to a disaster than I care to think. With the garage door raised, there's some scorching on the inside surface. The end of the output hose was melted (rubber hose) and there was flame in the catch tray around the fill cap.

Pretty scary, but no panic is what probably saved the day.

OBTW, the fire exenguisher was NOT at hand during all this. Couldn't remember where I'd stashed it and totally didn't think ahead of time to round it up. After it was all done, I walked right to it. <double head slap> :doh1: :doh1:

If you've not done something like this yurself yet, learn from my mistake. If ya have done, why didn't ya warn me!!! (Oh, wait, Honda tried to and I ignored it.)

Whew! Close one. And lipSTick will be ready to roll to Phoenix on Wednesday, soon's I swap out the rear wheel for the 16" with Taxi Tar.

GitSum, the PERFORMANCE ELECTRIC P06K does look exactly like the E-Bay pump from Hi-Flow in LA. AT $26 versus $80, ya gotta wonder. Either it's an inferior part or Hi-Flow is taking some advantage. I think I'll order one just for comparison. I've already wasted that much money just getting this far, what's another few buck$?
 
Okay, ordered the Performance Electric pump from Rock Auto. Turns out I already had an account there from 2010 but I don't remember what I ordered then. Wasn't a fuel pump tho. (Looked up the previous order, it was for Iridium plugs. They're current price is $6.40 each, still a good price.)

Total price on the pump is $33.23 with $6.40 shipping. Less than half the E-Bay price. We'll soon see. :D
 
If (as I suspect) the after market pump replaces the OEM 'lectric motor, the "fuel inlet" hose just goes where it always has on the stock assembly. No reason to suspect any diff. I'll 'let y'all know soon's the new one(s) arrive.
 
Time for George to hire a sidekick like Tonto. :D

Is there any chance this "mystery hose" is a burp hose to allow fuel to flow into the lower tank from the upper???
 
Not on the 1100, Jeff. The "upper" tank is integral with the main lower part, one piece steel tank.

Just found this note from Paul Kolbo on John and Becci's old web site (John Parker, LA). Just shows ta go'ya, the more things change, the more they stay the same. :D

<edit, add> <edit, change their to they're, I'm my own Grammar Nazi. :D> Looked up John over at st-riders. He's just coming off some serious medical problems (December last year), and I guess [-]their[/-] they're up on Oregon now. One of the long time STOC members, #124. Wishing you well, sir, and still a useful web source.
 
Glad you were able to avert a near tragedy George.

Here is how I was able to revive my OEM pump.

I originally took it apart to just see how it worked, but the only thing wrong with it that I could find was that it was pretty well "crudded up"

First of all - this is what the armature and magnets looked like once I pulled it apart! Geez, I wonder why it stopped working!
crud.jpg

I pulled the pump out of it's housing by removing the white nylon clip at the end
pump1.jpg

I used my trusty Dremel tool to slice the case open. I also had to pry up the tabs that fold down over the end piece. Not a whole lot you can damage unless you go really deep with the dremel
pump2.jpg

Here are the pieces starting to come out (this is after I semi cleaned everything up and put the pieces back in place for the photo)
pump3.jpg

Here are all the parts cleaned and ready to go. The white circular piece (top left) is actually the front part of the pump chamber. The large hole with the slot is where fuel flows in an get pushed out the circular hole which has a little nozzle on it. Look at the brushes - this pump ran for 100,000 miles and there is still plenty of material left
pump4.jpg

I put everything back and used that hose clamp to hold it together for now. I started sliding it back into the housing (it's actually a pretty tight fit) I just removed the hose clamp and slid it the rest of the way in. The slice in the casing didn't really seem to have any effect on the pump or it's performance
pump5.jpg

Here is a better picture of the components with the armature and magnets removed. The black impeller goes inside the housing directly above it and the armature has two 'forks' that fit into the two slots of the impeller. The larger nozzle on the left is for 'fuel out'
pump.jpg
pencil.png
 
You must log in or register to reply here.
Back
Top Bottom