94 ST1100 Fuel Pump Issue

secretoctopus said:
Okay I’m working on the bike today and I can confirm that I do not have this vacuum module at all. The fuel runs through the filter and right through to the left and to the carb bank as far as I can see right now. I haven’t taken off the air filter base yet to try to inspect further, but I thought it was weird that I don’t have whatever what vacuum module appears to be.
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Here is a video showing fuel tank wiring, fuel line, and trying to fire it up with the air intake boots off.


Original fuel tank wiring appears to be working normally, so no need to be jumping it with direct power all the time.

Fuel is definitely getting to the carbs as you can see it blowing around and then draining after the bike fires and dies.

Is this simpler than I thought? Just properly adjusted carbs?
 
ST1100 are notorious for fuel pumps, take the line off and pump it into a container. Sure does sounds like it's not getting enough gas. Take the fuel pump out and inspect it, the filter on the bottom of the pump and inside of the tank. very easy.
 
Al st1100 said:
ST1100 are notorious for fuel pumps, take the line off and pump it into a container. Sure does sounds like it's not getting enough gas. Take the fuel pump out and inspect it, the filter on the bottom of the pump and inside of the tank. very easy.
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I am able to pump copious amounts of fuel with the current fuel pump. I pumped quite a bit out a couple different times yesterday. But it does sound like it is fuel starved somehow still.
 
Rob20111 said:
Is the fuel filter oriented properly? Maybe check for a flow direction arrow on it.
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Good question, I did pull the line off after the fuel filter and made sure fuel could pump through he filter. Seemed like the same amount of flow as when I pulled the line behind the filter.
 
Erdoc48 said:
I can’t comment on the fuel pump vs relay as I don’t know, but very nice score on a free bike- if you do get it running, then you have a nice runner. I’m not sure but as my 94 looked the same (black with gold wheels), I wonder if it’s an ABS1 version. If it is and you’re having issues with the ABS system, the parts are no longer available- with mine, I just disconnected the ABS via pulling the fuses and ABS/TCS dash lights and made it a non ABS bike (and runs fine as such). I could never get it to work properly.
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Believe this is a 94 A not an AA model which has ABS. When I looked at the photo I did not see the ABS reluctor ring
 
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