Ducati.ms - The Ultimate Ducati Forum banner

Fuel hose keeps popping off

16K views 34 replies 16 participants last post by  DuckMan 
#1 ·
2000 ST4 , put a new fuel filter,clamps, and the gates fuel lines on about 1000 miles ago,
twice now the fuel line has popped off the fuel filter, The last time was about 100 miles ago, everything looks great, clamps super tight, it's the curved line. doesn't make sense why it keeps popping off, Did the same fuel service on my ST3 and have never had any problems, I'm thinking maybe the new filter is plugged up or the pump has too much pressure, has anyone ever had this problem?
 
#2 ·
There are really only two possibilities if you have a new filter and it is not in backwards (not even sure if that would cause it).

-The fuel hose is not the correct size. Should be 8MM (5/16).

-You have the wrong clamps or they are not tight enough.

This is what I used, along with the NAPA filter, and I have no issues.


 
  • Like
Reactions: dst306
#3 ·
Yes , that is the exact items I used except it is a Ducati filter, the first time i did it it was because the original rubber hose had turned to almost powder before they broke. I'm thinking that I didn't get all the crap out and it plugged up the new filter, I am going to replace it and the clamps again.
 
#6 ·
ok , just pulled it apart and everything was in correctly , the clamp was all the way tight ,could not be tightened anymore, (it was a new f15pb mini g clamp that I ordered on amazon, when I put on a couple weeks ago ,looked just exactly like the stock clamps , I also had put a brand new stock Ducati filter on at that time. The hose had popped off the input side of the filter, 2nd time this happened and I made sure last time that it was on good and tight ,this time I used a regular small automotive hose clamp that I could tighten all the way down without it bottoming out. There is no way this it can come off now. beware of using those clamps on a stock filter, they might work ok on a Napa filter but I think the flanged part of the tube on these new oem filters I got are not as pronounced as on the original one I took off . Now I am going to pull my st3 apart and check it.
 
#7 ·
I think the flanged part of the tube on these new oem filters I got are not as pronounced as on the original one I took off.
That's interesting. Haven't used a Ducati filter in a long long time so I don't remember what the flange looked like. I will say that the OEM clamps on my ST4s were just like those clamps on Amazon. I only replaced them because I had them. My old 900SSie had the crimped clamps that you see on other parts of the fuel system. Not sure why, but it did.

The NAPA filters are just fine. In fact, if you're worried about the loose fit, there is a guy selling adapter rings on eBay to fit the NAPA filter in the OEM filter holder. Haven't felt the need myself, but I know some are concerned about the loose fit.
 
#8 ·
I'm on my 5th NAPA fuel filter. I've only tigthened it on the flange with it cocked in the nylon clamp. It has yet to move. The fuel hose, esp the shorty, adds stability.

I've had issues with the hose coming off the pump nipple only because I didn't have the hose tightened enough. The bulbs on the NAPA filter and the lines out of the tank help quite a bit. I wish the fuel pump had a similar bulb. The porous nature of the fuel flange is pretty freakin' fantastic also.

As for clogging up, I've only found residue on the pump inlet screen once (the first time I checked when the bike had 24k on the clock). I've yet to cut open a filter only because of the flammability issue. . . and a fiery death. =)

Have a good one.
 
#10 ·
Are you using the proper hose? The hose LT sells is too thin walled to be used with the standard 5/16 injection clamps. If you used regular FI line that was not rated for in tank service it might be turning to slime and poping off.
 
#11 ·
I used LT's R7 line when I swapped out the OEM hoses (at 36k, I think). Yes, the OD of LT's hose is smaller than the OEM hose. You cannot reused the OEM clamps with that hose. I went to NAPA and picked up some appropriate sized clamps that have worked fine.

The neat little clamp making tool that LT sells is excellent for other stuff including the vent/overflow lines, but not good for pressurized fuel lines. It works great for the brake/cluth fliud lines from the reservoirs, esp with the clear line.

I know LT says differently about using it at the pump and filter, but that is just my experience.

The other, much talked about, option is to move the FF outside the tank. Here, you can just run the whole 1ft section of R10 hose from the pump outlet to the flange. You do want to install the filter on the "M" (feed) side to prevent any junk from getting to the injectors. This is on my to do list, someday, along with quick disconnects.

Have a good one.
 
#12 ·
The other, much talked about, option is to move the FF outside the tank. Here, you can just run the whole 1ft section of R10 hose from the pump outlet to the flange. You do want to install the filter on the "M" (feed) side to prevent any junk from getting to the injectors. This is on my to do list, someday, along with quick disconnects.

Have a good one.[/QUOTE]

If you move the ff outside the tank, is it then downstream of the fuel pump giving the pump no filtration?
 
#14 ·
Hey Max, have you come up with an external plumbing set up for the filter outside the tank. I'd thought I would do it one day but space seems limited.
 
#15 ·
No I never have Robert. Changing the filter externally would still require draining the tank of fuel and still be quite bothersome and messy. I have no problems with pulling the tank and removing the plate. It also affords me the opportunity to inspect the tank and clean the intake screen on the pump. I do that every 2 years when I replace the belts.
 
#16 ·
You don't need to drain the tank to pull the external lines / tank. Although, the fun part from me is always the residual amount in the injector circuit when I do pull the tank. The Wife will complain about the fuel smell. For a while now, I've been thinking of fitting metal QD fittings (and possibly rerouting one of the lines directly forward over the head, but I don't know the thread on the banjo for metal lines. It was said that it isn't the typical QD tread. But, McMaster Carr has a bunch of different threads listed for the QDs. $78 worth of fittings puts me off as an expensive experiment.


Robert,

Congrats on the find. Although, I had hoped that Fishmonger's SST would have made the trip cross country.

Have a good one.
 
#17 ·
Robert,

Congrats on the find. Although, I had hoped that Fishmonger's SST would have made the trip cross country.

Have a good one.
Hey Tony, I'd really planned to go with Fishmongers, I think what he's done is
the best complete build on an ST4s. But, when I factor in the shipping and the extra bucks and I found one nearby for 6500 with less than 10k on the clock...
well, you get my drift.
Have a good Christmas out there!
 
#20 ·
LOL. I'm the same way about tank removal and the clean look. Pulling the tank is by far the most miserable part of the work. I'm glad it hinges up for getting to the air box and rear plug.

My thought was to put the QDs closer to the throttle bodies, like right there at the TB fittings. Reasoning was you would move the fuel lines out of the way of the belt covers when removing the tank, and it would still allow the tank to easily hinge up like it does now. Not 100% sure you would get away with putting the QDs at the pump flange. Clearance may be an issue and the stress at the fittings from lifting the tank may also be an issue. On the SBK, with the QDs at the pump flange, there is enough room for them over the rear head and the tank does not hinge up at the rear. There is a bolt at the rear and a pin at the front that fits in to the air box. Very different set up than you would find on the ST, SS or Monster. You unbolt, slightly lift the rear of the tank and un clip the QDs and slide the tank back to remove. Not much extra hose provided there. My concern for the ST doing it that way I describe was access to the QDs without removing the fairings. I think it could be done if you reach through the fairing air conveyors. Anyway, that's my plan...
 
#21 ·
Those are convincing arguments. I was thinking about the rotation issue and how much slack would be necessary. The flange is fairly close to the pivot. I was thinking of testing the idea with some rope.

Inline solves most of the problem.

I do appreciate that the tank does pivots up fairly easily.

Have a good one.
 
#22 ·
I fitted QDs to my 4s a few years ago. Originally I put them next to flange but there isn't a lot of room there and you end up with about 3" of rigid pipework composed of the couplings. This made it very awkward to get the fuel lines to lie without putting a stress on the QD couplings. They are also close to the exhaust and suspension rocker. The following winter I moved them to the opposite end of the lines, close to the TBs. The are a bit harder to access but present no problems there and I'm much happier with the fuel line route where they come off the flange.
 
#23 ·
Time to resurrect a 3 year old thread.

I am having the same problem and I don't see where anyone has come up with a better holding clamp idea. I am having a problem where the small horse shoe shaped hose is coming off on the fuel pump side. I tried double clamping it this last time with a brand new 5/16" fuel pump hose and it came off while idling immediately after fixing it. I didn't even get to ride it. The time before that I rode it about 5 miles before it popped off again. I am using the clamps that you screw to tighten. The ones with the holes or notches so you can tighten all the way down. The hose is very tight when i try to pull it off by hand.

Is there some kind of glue I can use to just glue it to the fuel pump nipple? Did anyone ever find a working solution?
 
#35 ·
I safety wire mine. For a while I tried using the clamps like Max suggested but never seemed to have exactly the right size clamp.

I wrap the safety wire around the hose three times the tighten using safety wire pliers. Never had one pop off yet. You just have to be careful and not over tighten cutting the hose.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top