Article [11] ST1100 - Fuel Pump Replacement

Well, started RedBird up this morning for the ride into work and everything worked as 'normal'.
It was 32 degrees in the garage and required the 'choke' (fuel enricher) to be applied.
Fired right up as it should and ran normally all the way in.
So looks like the regulator and the pump are functioning as I had hoped.
I'll keep this thread updated as I get more miles on this setup.
 
Jeff Prest said:
I cant help you with the terminal issue but I did find a solution to the aftermarket internal fuel pump overpressure problem. You will cause problems for the carbs with too much pressure. I purchased a $50.00 aftermarket internal pump that was supposed to only produce 2psi. I installed the pump in the same place as the original pump and replaced the 30cm rubber pipe just in case. As long as you make sure your exposed terminals are tight there will be no issues with it being in vapor or liquid. After re installation of the whole assembly into the tank I thought id just check the pressure to make sure it was right as not always do items perform as advertised. It was outputting 20psi and this would have completely overpowered the carb floats. The original pump assembly bypass is literally to remove excess pressure. On the new 30cm rubber pipe between where it came off the new pump and before it left the tank through the top hose connection I drilled a simple hole with a 4.5mm drill bit approx 1cm from the pump outlet. By doing it down low it reduced any chance of frothing. Works a treat and its now been 3 months trouble free.
Click to expand...
Jeff,

What did you measure the pressure at after drilling the hole?

Jeff
 
Hello again,

Been watching this thread since I last posted in October... Possibly started having issues again with my external (Facet) pump, so I went ahead and took the plunge. You may recall - I had a Quantum pump - but the pump "harness" where the positive electrical wire lug connects on top of the tank had broken off and there was no where to connect anything.

I ended up just popping the little plastic cap off of where the lugs come out (did not know that was a cap - thought it was all one plastic piece) and there was plenty of metal there to solder wire on. So I did and removed the female lug from the wire and made a direct connection..... I hope I won't be removing the fuel pump so often that will be an issue :).

I looked and looked and could not see any markings on the Quantum pump showing which was + or -... so I took a shot.... then, as expected reversed what I had to make it spin the right way.

So - all seems well - although I do believe I am experiencing the same issues you guys are... bike will start cold without the choke. I only took it out for a short spin - 30 miles - and stopped once for maybe a minute or two halfway. It did seem like the bike turned over a few more times than normal on restart, AND - the idle was up by a few hundred RPM... say from 1200 - to 1600/1700 ish? I adjusted that at my halfway stop - but I know that is not cure - just a bandaid.

So - I plan on looking into the pressure regulator talked about earlier - but are there any other things to look for... or work arounds, or something to "prove" these issues are caused by over pressure?

I certainly appreciate all the leg work you guys have done and the info provided on this issue. Looking forward to doing some tinkering.

Odie1
 
I now have several thousand miles on my Redbird that has the Quantum Pump and the Chinese regulator set to 1.5 PSI and it is still working great. Choke works like it is supposed to and according to my 'butt' dynamo I am getting better gas mileage. :biggrin:
 
Following this thread since I own an 1100. The Facet option is interesting although has proven not reliable, correct? How about a Quantum pump that is designed for motorcycles, AND is external to the tank? Would this not work as an "oh crap, get me home" option? Or a permanent install? Only because I saw it on the Quantum site....

www.ebay.com

QFS Electric Fuel Pump for Honda VT1100 Shadow 1100 VT1100C VT1100C2/C3 | eBay

You will not find a stronger warranty from any other performance fuel pump manufacturer, period. Compatible with modern ethanol-infused pump gasoline. Gradient density fuel strainer for superior contaminant filtration.
www.ebay.com

RT
 
rwthomas1 said:
Following this thread since I own an 1100. The Facet option is interesting although has proven not reliable, correct? How about a Quantum pump that is designed for motorcycles, AND is external to the tank? Would this not work as an "oh crap, get me home" option? Or a permanent install? Only because I saw it on the Quantum site....

www.ebay.com

QFS Electric Fuel Pump for Honda VT1100 Shadow 1100 VT1100C VT1100C2/C3 | eBay

You will not find a stronger warranty from any other performance fuel pump manufacturer, period. Compatible with modern ethanol-infused pump gasoline. Gradient density fuel strainer for superior contaminant filtration.
www.ebay.com

RT
Click to expand...
Any 'external' pump with close to the right pressure would probably work.
I just made up an 'extra' stalk with the pump in place so it would be an easy swap.
 
Want to add I am not sure I had an issue with the facet pump. Was having troubles on the road and "fiddled" with it. Then all was magically good again!? Rode home for an hour with no further issues. So, it certainly could have been something else, but sure seemed like a fuel starvation event.

I honestly did no further testing, and might have the same issue when I go out with the Quantum next time.

Just FYI. Did not mean to positively blame facet.

Odie1
 
Odie1 said:
Want to add I am not sure I had an issue with the facet pump. Was having troubles on the road and "fiddled" with it. Then all was magically good again!? Rode home for an hour with no further issues. So, it certainly could have been something else, but sure seemed like a fuel starvation event.

I honestly did no further testing, and might have the same issue when I go out with the Quantum next time.

Just FYI. Did not mean to positively blame facet.

Odie1
Click to expand...

I've used Facets in several vehicles and never had a problem with them, not one. However they do seem to be a bit oversized, even the low psi models still have high gph ratings. I have doubts about pump outputs being overly restricted and longevity. The MC pump is designed for low pressure AND low gph. Seems more appropriate.

RT
 
Yesterday while descending Hwy 40 in the Unita Nat Forest In Utah, my bike died. According to the woman I flagged down, I was about five miles from cell service and ten from a gas station. It was pretty warm out, and I had made a number of stops to shoot pictures, but I was also about 230 miles into the last fill-up. I brought a quantum pump, but I really, really didn't want to attempt a field repair so I did some checking. I could see the filter was full as a small bubble bounced around as I moved the filter around, and when I pulled the fuel line from the tank nipple and hit the key, it seemed to pump fuel, although I don't know what the correct amount looks like or have any way to measure pressure. With the enrichener on I could get it to start and run for a few moments, but touch the throttle and it would die. So it sort of seemed like fuel was being moved, but maybe nowhere near enough pressure? I decided to reload my gear and wait it out since it was early in the afternoon and a cool wind was coming down the hillside. And like many of your experiences it finally fired up and acted like nothing happened. Reminds me of trying to pull-start the lawn mower as a kid after refilling when it was hot out - vapor lock.

Does a new pump just fix the issue, because I'm pretty close to just buying a new pump and experimenting with the old stem and the quantum pump + factory regulator. I'd rather just install the Quantum, and they say it's a direct replacement, but now I feel like I want to measure the pressure output.
 
Have you bypassed the vac. valve? It's right by your knee under the plastic, mounted to the air filter housing.
 
If you do not use a regulator with the Quantum, the pressure will be too high though they say it is 'speced' for a ST1100.
( have already discussed this in length with them).
The sure sign is you will not need to use the 'choke' when cold.
And you will need submersible fuel line (very expensive) not the stuff that Quantum provides.
 
Sorry, yes I already removed the vacuum valve so I'm pretty sure that wasn't my issue. :)
I'll probably just buy a new pump and then play around with the Quantum + regulator or ask them to take it back. Seems hard to believe nobody makes an actual low-pressure pump that really is a drop-in replacement, but I think someone in this group would have found it by now. And yeah, the bendy plastic line they provide doesn't make me terribly confident other than emergency use.
 
I'm going to order one just in case. STerling has only 40k miles but sat idle for a long time. My observations indicate dirt is an issue with the stock pumps.

Thanks for your research, Phil.
 
Uncle Phil said:
If you do not use a regulator with the Quantum, the pressure will be too high though they say it is 'speced' for a ST1100.
( have already discussed this in length with them).
The sure sign is you will not need to use the 'choke' when cold.
And you will need submersible fuel line (very expensive) not the stuff that Quantum provides.
Click to expand...

What's required for the regulator?
 
George - I bought a cheap external Chinese regulator on EBay and set it to 1.5 PSI after trying other settings. So far in close to 4,000 miles of riding the set up has continued to work well. I carry a 'stalk' with a Quantum installed and an extra regulator in my right saddlebag on any long trips I take. I'd rather have it and not need it as to need it and not have it!
 
Well, a year or so later (and many more miles) and the replacement fuel pump and regulator are still performing well.
I still haven't figured out a better mounting scheme for the regulator that to tie-wrap it to the old shut valve bracket.
But I'm still noodling on that one! :biggrin:
 
Right after I bought the 1991, I started collecting up spares based on discussions from this site. Just an OCD habit from my restoration habit/hobby. I found Ebay deals for a new sending unit and pump assembly. During my refurbishment 18 months back, I found much rust inside the upper cavity of the gas tank. Got a tank that a breaker removed from a wreck...and he dropped it, honking up the left front mount tab. I got it cheap, under $20 with no rust or other dings and fixed the damage with vicegrips and a pull hammer, a fresh coat of paints and the whole assembly is new or new so. Deals are still out there if can afford to be patient.
The fuel pump assembly from the original tank still works and looks good, but will get a new pump per your suggestion. Already have the spare pump and submersible tubing. Thanks for posting these how-to's, UP.
 
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