Weak prime

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kdawg302000

Well-known member
Joined
May 25, 2015
Messages
82
Location
FREEDOM, CA
Hello all,
Been a solid year since I have had a problem with Gwenevere, but I'm back and I think she might have caught the Rona (or just playing hooky from work).

I have read through about 300 threads and my eyes are crossing. I have an idea on what I need to do, but would like some confirmation.

I haven't come across my exact problem in the threads, but similar and worse problems.

Took a 200 mile round trip run about 2 weeks ago. About 20 miles into a 100 mile return ride I stopped for gas. Filled up and the bike she didn't want to start. Turned off, did a TPS reset, turned back on, fired up.

literally at mile 100 of 101 mile trip bike starts acting fussy and didn't want get up anymore. I backed off and just cruised. At mile 100.9 of 101 the bike cuts off and I roll into my driveway. Talk about luck. I try to start the bike back up, but just keeps cranking, but won't turn over.

Bike turns on, light sequence on point. When I flip to "run" the bike has a really weak prime, like there is a clog or failure in the pump.

Troubleshooting:
Replaced Batter (mainly because it was time)
Checked all fuses
Checked all relays
checked wires (all appeared to be well)

I'm guessing I need to replace the pump, or atleast pull it and check, wires, sock, etc...Am I missing something?

I would Ride down to Cooter, but well I Ain't towing her on the back of the Heritage.

Do your worst.
 
forgot to mention there are no error codes on ECMdroid. I also ran all the active tests, and the pump does nothing at all when I try and test it there.
 
Weak prime. I prefer Optimus Prime. Freedom is the right of all sentient beings.
 
A failing fuel pump will most times exhibit nearly all the symptoms you just described. Included will be occasional excessive amp draw harming the key switch relay...inaccurate and/or failing low fuel sensor.....cold fuel frame normal prime but failing to prime and charge as the fuel increases in temp. A failing pump motor will show 40PSI or less when tested and most often randomly pop the 10A fuse. A healthy pump motor only draws approx 60 watts and when the motor is failing the draw will be in excess of 125 watts, or more, popping the fuse.
Ref your twist-and-go TPS reset remark...must be a 2008-2009 model. Very easy to properly rebuild with the correct parts. If 2010 model, quite a bit more difficult.
I would:
Remove and clean frame sump
Strip down pump assembly and replace only the high pressure feed line---5 O-rings----fuel sensor---high pressure filter---suction intake sock filter----high pressure filter bushings. Pump motor probably fine. They rarely wear out.
 
And you can even get the parts from ^^^^^^^^^^^^^^^^^^^, guess who.

P.S. sorry, I left out that you will also get a discount which is extended to forum members.
He used to offer beer but that was before Cooter stopped by.
 
Last edited:
A failing fuel pump will most times exhibit nearly all the symptoms you just described. Included will be occasional excessive amp draw harming the key switch relay...inaccurate and/or failing low fuel sensor.....cold fuel frame normal prime but failing to prime and charge as the fuel increases in temp. A failing pump motor will show 40PSI or less when tested and most often randomly pop the 10A fuse. A healthy pump motor only draws approx 60 watts and when the motor is failing the draw will be in excess of 125 watts, or more, popping the fuse.
Ref your twist-and-go TPS reset remark...must be a 2008-2009 model. Very easy to properly rebuild with the correct parts. If 2010 model, quite a bit more difficult.
I would:
Remove and clean frame sump
Strip down pump assembly and replace only the high pressure feed line---5 O-rings----fuel sensor---high pressure filter---suction intake sock filter----high pressure filter bushings. Pump motor probably fine. They rarely wear out.

Thank you for the write up. Now take my money and tell me how to get you my address so you can send me the lot?
 
Yeah what Barrett said. The pumps being the same as some oem passenger cars and trucks that usually get 180 to 250 thousand miles on them with just a filter change every 30k. Still might be time though if high draw and bad grounding can cause starters and other electric and electronics to fail.
 
Ok. I know its been a couple months, but that is what my life has turned into with kids, sports and a divorce. Barrett sent me some a couple pieces and I got the rest from Revision. I rebuilt the fuel pump and re-installed. 1st positive is that it primed as soon as i set it to run. 2nd positive is that the bike started to turn over like usual. 3rd positive is that the bike started and I started to get a funny feeling down below. That ends the positives. She then sputtered and died. tried to start again, same thing. Figured it was the air trying to get out of the system. Tried a couple more times. each time, it starts, idles fine, then starts to get sporadic on the rpms and dies. I'm guessing this is regulator related, but now im stuck again. any ideas before I pull it apart and start over? I feel like its pressure regulator related. but what do I know.
 
I would check the fuel pressure first before pulling it back apart.

If you think its an air pocket, you can purge it by removing the fuel line at the injector rail and cycling the fuel pump. Just be ready with a container to catch the spray of gas. The pressure created by the pump should be able to easily expel the air and any remaining should be cycled through pretty easily while cranking.
 
Alright, so im back at it again. Seem that the air is out of the lines. Im confident I did the pump correctly. I started researching my issues and it seems common. Starts, idles fine, 30 seconds in, it starts getting all erratic. I pulled my spark plugs and they are black as night. So, i have some carbon fouling, i belive that means im too rich. Is that the only cause? Or could there be another issue. I also think i jacked my boot on the front plug when i was getting it off. Smh.

Gonna go get some new plugs and see if that fixes the problem.

Any other suggestions?
 
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