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Discussion Starter #1
I started the bike and noticed fuel smell as I was driving away so I looked and saw fuel spraying out of the connector on the fuel tank. I turned around and parked it at home and read about the fuel fitting problem so I ordered the fittings from omega and finally got them and put them on. bike wont start now? it will crank and once in a while start then in a second or two die out and it sounds like it is getting choked. I pulled off the tank and rechecked the lines, fittings , all connections and still nothing, I even just pulled off the fuel rail and fuel jets thinking it was clogged and nothing??aloha
garett
 

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I don't suppose you could have reversed the in: out? I think the fuel pump fuse as above would prevent any start, do you hear it cycle when first turning the key?

Could a fuel line be crimping once the tank is reinstalled? They are sometimes difficult to orient. Have you tried to lift it off the frame and start?
 

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Discussion Starter #4
I checked lines and they are not pinched as I can see them thru the right side easily. can the fittings be reversed? I was wondering about that but it looks like they both go into the same fuel rail just on both side? I marked where the black one goes with a sharpie then made sure I put them in right but the sharpie was hard to see after I handled the fittings.
fuel pump turns on when I turn the key it goes on for the first couple seconds then when I crank it stay on for a second after I stop.
I will try reversing the fittings
 

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Garret
Hope you sorted out your fuel issue. Do you have a competent mechanic on Maui to work on your bike? I have yet to find one on Oahu. figure I will do my own wrenching when I ship the bike from the mainland.
 

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Discussion Starter #7
After fighting with this problem for a couple weeks of taking everything apart too many times I finally found the problem hopefully. The fittings I got from omega had black orings on them was swelled and plugged the fuel from moving. It was the orings that go on the fitting that goes into the fuel tank bottom. To remedy the problem I first tried replacing the oring with another one but it too swelled and eventually blocked the fuel movement. I then took off the oring completely and now it seems to work fine.

I broke the bolt that holds the fuel tank down by overtightening it one too many times, anyone have one to sell?

MvAli I do the mechanic work myself on my bikes. I use websites like this one to help me figure out problems and also get info on upgrades which is fantastic :yo: Part of my hobby of owning this bike is trying to wrench it..

aloha
garett
 

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Garett,

The problem was o-rings inside the female end of the fitting?? They are dry breaks, when you have fuel in the tank and remove the male end does fuel not spill out? I can't remember offhand but believe the oring on the female side is the plug for the drybreak, no? While the oring on the male side is the seal when they are joined..
 

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I don't think connecting them the wrong way around would make any difference.......... the fuel pressure regulator is in the tank, not on the fuel rail like a car, so all that would happen is the fuel would go through the fuel rail the other way, it would still be regulated for pressure on it's return to the tank :)
 

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mikef4uk said:
I don't think connecting them the wrong way around would make any difference.......... the fuel pressure regulator is in the tank, not on the fuel rail like a car, so all that would happen is the fuel would go through the fuel rail the other way, it would still be regulated for pressure on it's return to the tank :)

I assumed there was something shaped in the rail to make it matter, otherwise why bother with the colours? Just to define where the lines lay under the tank maybe?
 

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JamesC said:
I assumed there was something shaped in the rail to make it matter, otherwise why bother with the colours? Just to define where the lines lay under the tank maybe?
Maybe just to keep everything side by side etc and not getting trapped? I would imagine they could get messy if you crossed them over, there's little enough room there any way,
I can't see why it would matter after all it's only a fuel rail, the pressure reg is inside the tank were the fuel returns :)
 

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Discussion Starter #12
It was the female end. there is a plastic pin with a spring and on the other end is the oring which is suppose to be smaller then the diameter of the fitting so fuel can pass. it swelled to the size of the fitting so no fuel can pass even when it is actuated open. I am kinda pissed at this problem becouse it would seem that omega didnt put a fuel resistant oring as I think they are suppose to be a special kind of rubber. Something so simple as a oring crippled my very expensive bike :banghead:

aloha
garett
 

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mvmaui said:
It was the female end. there is a plastic pin with a spring and on the other end is the oring which is suppose to be smaller then the diameter of the fitting so fuel can pass. it swelled to the size of the fitting so no fuel can pass even when it is actuated open. I am kinda pissed at this problem becouse it would seem that omega didnt put a fuel resistant oring as I think they are suppose to be a special kind of rubber. Something so simple as a oring crippled my very expensive bike :banghead:

aloha
garett
Do you know where I might get a fuel-proof o-ring replacement? I've got a brand new set of Omega fittings waiting to be installed, and I'd like to swap o-rings beforehand. Thanks.
 

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Discussion Starter #14
anyone knows the size of the large oring that seals the bottom fuel tank plate?
 

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mvmaui said:
After fighting with this problem for a couple weeks of taking everything apart too many times I finally found the problem hopefully. The fittings I got from omega had black orings on them was swelled and plugged the fuel from moving. It was the orings that go on the fitting that goes into the fuel tank bottom.
I confirmed the o-rings on my new, unused Omega fitting are also not gasoline resistant. I took one off each fitting and put them in a jar with some gasoline, and after a few hours they began to swell. They must be using rubber, but they need to use Viton or Fluorosilicone o-rings for fuel line fittings. I tried the local auto stores, but the only Viton rings were in a small assortment pack, so you can't be sure you're getting the right sizes. Thanks for finding out about this before I installed my fittings.

Has anyone contacted Omega about this to see if they have Viton replacements?
 

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JamesC said:
Garett,

The problem was o-rings inside the female end of the fitting??
James,
I checked the McMaster web site for the Viton o-rings you indicate in your blog. The ones you suggest replacing regularly are not the same ones. I found the matching size Viton o-rings for the dry breaks. They are AS568A-008, McMaster part # 9464K13 and currently run $6.03 per pack of 100. Might want to make a note of those on the blog, as well as the gist of this thread.

The larger ring that seals the coupling (AS568A-011) is # 9464K16, $7.54 per 100. It really sucks that the fittings are not supplied with fuel-proof (pun intended :naughty: ) o-rings. This makes me wonder if the white plastic bits will hold up to gasoline over time??? Have you seen any degradation with those?
 

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Yes, those are not the ones I have on the FAQ because this is the first time I've ever heard of a problem with those o-rings on the female end, while the orings I have listed on the male end are a frequent issue. More frequent than broken fittings IMO.

There are a ton of people out there running the metal fittings so why have yours swelled?

Burst/loose hoses to the pump, yes
Broken fittings, yes
Clogged by it's own o-ring, first for me

Very strange. Let's call them after the holidays.

EDIT:

The ones I have listed are mcmaster pn: 9464K16 at 7/16 inch O.D. by 5/16 inch I.D. by 1/16 inch wide and are for the MALE side

The one you listed as mcmaster pn: 9464K13 at 5/16 OD by 3/16 ID and you are saying this is the size for the female side?

The white plastic parts were fine on my bike until mid thirty thousand miles.
 

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JamesC said:
There are a ton of people out there running the metal fittings so why have yours swelled?
Clogged by it's own o-ring, first for me

Very strange. Let's call them after the holidays.

EDIT:

The ones I have listed are mcmaster pn: 9464K16 at 7/16 inch O.D. by 5/16 inch I.D. by 1/16 inch wide and are for the MALE side

The one you listed as mcmaster pn: 9464K13 at 5/16 OD by 3/16 ID and you are saying this is the size for the female side?

The white plastic parts were fine on my bike until mid thirty thousand miles.
James, I haven't installed my fittings yet; they were still in the packages. I just tried soaking one each of the fittings in gasoline to see if the o-rings would react, and they did swell up quite considerably. However, even after sitting in the jar overnight the internal ring on the female was not swollen enough to completely block the opening, though it could be enough to restrict the volume of fuel and cause the problem Garrett described. Maybe more time is needed, but in any case I wasn't thrilled that it swelled at all. It may disintegrate completely over time.

I removed the smaller o-ring from the female fitting that was not in the gasoline and went to Ace hardware to find a match. It was a perfect match to the 5/16 OD by 3/16 ID x 1/16 Ace #36 o-ring (stock number 35750B). That's how I determined the correct size. I also found some blue ones at O'Reilly's auto parts, but both substitutes also swelled after soaking overnight, so nix them as a source.

I emailed Omega about this, and asked if they can provide Viton substitutes, but I'll probably call them Tuesday or Wednesday anyway. I'm curious to know what they are using. I couldn't find any info on their web site saying whether these fittings are intended for use in fuel lines or not.

I'm glad that Garrett was able to determine the cause of the problem. That's some good detective work.

Do I take it you had to replace the Omega fittings after 30K miles because the white plastic was degrading?
 

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mvmaui said:
anyone knows the size of the large oring that seals the bottom fuel tank plate?
Not sure, but if you are struggling to get an MV one, the Ducati 916 range has EXACTLY the same "O" ring...........and filter..................and pump..................and pump mounting :)
 

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falcopilot said:
I emailed Omega about this, and asked if they can provide Viton substitutes, but I'll probably call them Tuesday or Wednesday anyway.

Do I take it you had to replace the Omega fittings after 30K miles because the white plastic was degrading?
Sounds good. We'll update the page depending on what they say but I'll be surprised if fuel is a problem. There are so many out there...unless, since both of you got them recently..they have changed the oring material?

I was swapping my fuel filter in my primary tank anyway so since I had everything apart thought I'd go ahead and move to the metal ones. There was still no problem with the plastic fittings but you do have to be careful with handling them. No idea how many times I've had them off and on without incident but it would be a fair few I promise you.
 
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