Having issues with my 94 st1100 bike dies at half tank

Sledneck

Joined
Feb 28, 2022
Messages
4
Age
29
Location
North dakota
Hey guys just thought I’d pick some brains before I start working on my bike. The issue I’m having is once you get down to about half tank of gas the bike starts to stall out and die. As long as you keep your tank above half it runs great and haven’t had issues. But as soon as half tank comes around she will just sputter out. Purchased a new fuel pump havnt installed yet, just wanted to know if I’m looking in the right direction? Thanks!
 
That'll probably do it. Is it a new or used Honda pump or after market one? The Honda pump is pretty painless install.

Have you tried any trouble shooting on the problem?
 
Aftermarket fuel pump I’ll go grab the numbers off it. And I haven’t tried much for troubleshooting it. I do know that every once in awhile it sounded like you would here the pump make noise after you shut the bike down. Itd make a noise then quiet for 5 minutes then make a noise again. I was riding to work one day when all of a sudden bam bike started to die on me and I had half tank still(according to the fuel gauge). Had a buddy bring me gas thinking I was out and once I put 2 gallons in it ran just fine.
 

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Sledneck said:
I do know that every once in awhile it sounded like you would here the pump make noise after you shut the bike down. Itd make a noise then quiet for 5 minutes then make a noise again.
Click to expand...

That is a normal noise. Often described as a farting sound, it is the result of pressure building up in the tank from fuel heating and then being vented through the filler cap.
 
Possibly stupid question;
Did you check, and do you know that your fuel gauge is accurate?

i.e.
When the gauge reads a half tank, is there really half a tank of gas, or is the tank actually empty?
 
If the fuel pump isn't working, it will have a problem pumping the first half of the tank into the carbs, not just the last half.
I'm with @Andrew Shadow - open the filler cap the next time that it does it. See if that cures it. If it does, you can close the cap again to go riding, but you may have to repeat the operation every so often.
 
Thanks guys! And the snows a melting and the bikes about ready to go! Will say I put some bright a$$ led’s in it as well as 2 6” led light bars mounted to a bracket above the headlight! Helps since I do a lot of riding at night! First motorcycle I’ve own. Put 10k on for miles last summer and it’s only got 42k as it sits paid barely $350 for the bike and all it needed was a battery.
 
If it is always at 1/2 tank, then I would definitely look at the gas cap venting.
Fuel pumps that are flaky usually quit at odd times.
The fuel cools the pump but at a half tank it should still be well covered.
When it stops will it crank right back up?
The next thing would be to pull the fuel line off and see what the flow looks like.
 
Ron said:
The vent line on the tank freely flows air both ways.
Click to expand...
As I recall, there is a vent valve in the cap that controls both the direction and the amount of air flow. While the line free flows air in both directions, the vent valve in the cap that it connects to does not.
 
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