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Discussion Starter · #1 ·
So after multiple times of having the tank off this BRUTALE is still giving me issues:
The usual hose pop off thing happened. So I got the new submersible fuel line and re did it with a new correct MAHLE fuel filter and reused the OEM Clic-R clamps and then it was leaking where the hose meets the discharge of the pump. I then pulled the tank apart a third time and used fuel injection style clamps on everything and they are as tight as can be. Went to ride last night and stars and idles fine but when trying to ride and giving it gas it want to fall on its face. The more throttle I give it the more it stumbles and falls on its face. Once I limped it home (it was getting dark) i opened the fuel cap and when I go to turn it on and the pump primes it now squeals a little noise and i see little tiny bubbles come from where the fuel line attaches at the discharge of the pump. This is getting really aggravating and don't want to have a bike that is going to keep giving me issues. I'm thinking about just ordering the OEM fuel line as the Gates Submersible hose looks to be a slight different thickness to the rubber and the inner diameter..:(.
 

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Old Wing Nut
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Something ain't right here..... Chuck lives up the road from you in Massachusetts...maybe he can give you a hand.
At least the tank and pump plate are quick and easy things to work on, so you have that going for you.
 

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Ok, stand by for a few questions:

Which Gates hose did you get? Dimensions?
Are you certain there are no kinks in the lines that go to/from the fuel rail?
Did you ensure the CPC connections on the fuel pump plate are seated?
Did you inspect the O-Rings in the CPC fittings?
Is the fuel filter installed with the flow arrow pointing away from the pump?
Did you Barb the fuel pump outlet?

Im sure there is something (probably simple) in the fuel line system that is causing your stumble. For me it was incompatible make and female CPC fittings.

Feel free to reach out here or via PM.
Chuck.
 

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Discussion Starter · #4 ·
Good afternoon Chuck.

I purchased a foot of hose from you so that should be good to go
The new CPS fittings I purchased from ALEX at MY GP Racing and are the matched metal set that was installed with the proper Loctite sealant
The O-Rings are brand new on the CPC fittings as they are a brand new matched set
The fuel fuel filter is installed correct with the arrow facing in the correct position.
I did not BARB the fuel pump but used a new 13-55mm Fuel Injection Hose clamp instead of the facory Clic-R style
When shining a led light into the tank and hitting the pump to prime I see very tiny bubbles come out which looks to be coming from where the new hose is attached at the pump (discharge) and the clamps are pretty darn tight.
 

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Those bubbles are more likely from the fuel pressure regulator outlet tube than anything else.

My suspicion is the CPC fittings not being fully seated, but that is a tough call from here.

Did you do any other maintenance?
 

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Discussion Starter · #6 ·
Just oil change and new filter. THe bike has less than 10,000 miles on it and I took it for a ride Sunday quick and it ran fine which is what is aggravating me.
 

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So, it runs fine, the maintenance is done….and now it doesn’t run well.
The old mechanic’s adage come into play: The new problem you are experiencing is directly related to the maintenance you last performed.

Check your work.
 

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Yeah, I had an issue where the o rings had displaced in the female CPC fittings and were blocking fuel flow out. There is a pressure relief valve built into the fuel pump that is next to the barb and connector and fuel would shoot out from there (I had less than half a tank when this occured). Makes an interesting noise, too. My guess is something obstructing the fuel going out downstream of the fuel pump.
 

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Discussion Starter · #9 ·
Working on it now and I drained it to aclow fuel level and while shining a light in the tank it seems as the air bubble are coming from that small little open vent hole on top of the pump possibly, what is that small little vent hole with a screen on top of the pump.
 

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That little hole, if it's the one I have pointed out, appears to be a ball check valve that relieves to the fuel tank if the pump is putting out excess pressure.
IF that ball-check valve is fouled with some sort of debris, the fuel system will be robbed of pressure.
There is a Fuel Pressure Regulator (Red Arrow) that regulates return pressure to the tank in the Fuel Injection Loop that returns excess fuel to the tank via a 90 degree bent hose (Green Arrow).


486746


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486751
 

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Discussion Starter · #11 ·
That is it. Even though the pump has less than 10,000 miles on it im almost thinking of installing a new one as this is becoming very aggravating and don't want to be left stranded somewhere. I know the fuel pump is a somewhat popular BOSCH unit. What is everyone running or buying for new fuel pumps that doesn't break the bank and have been having good luck with? I was hoping there was possibly a Japanese unit like a denso or something as I've found the Japanese stuff less problematic than it's German counterparts?
 

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486752


Prices are going up.
This is what I get off Amazon
 
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Vendor
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Check your fuel fittings are opening fully to give proper fuel flow.I had a bad fitting awhile back giving the same issue as you and yes they were CPC.
I also use double ear clamps on my fuel hoses and never had an issue.
 

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Discussion Starter · #14 ·
I got it fired up and don't think it could be the pump as it primes and starts and idles. With it running and about a 1/4 tank I can see the fuel gusing out of the top of the pump from the relief valve. The cpc connectors are the brand new metal ones that were a new set from MY GP racing. Im hoping I don't have to break the seals and pull the whole fuel pump plate assy. out again. Going to go out in the garage now to try and diagnose this pain in the arse bike of mine..😆
 

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If that relief is lifting, then the system is being blocked from delivering fuel to the fuel rail and return line.
Check the connection at the fuel pump outlet. Then follow the hose to the fuel rail and check for kinks and check the fuel rail connections.

486760
 

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Did you inspect the screen (#13 in Chucks post #10) under your pump? Is your tank clean as a whistle?
 

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I have the listed pump from Amazon in one of my bikes and I have installed them on other bikes I have repaired. I have on sitting here in a box for the next time I need a fuel pump.
It is a like-for-like replacement.
 
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