Fuel pump - winter maintenance - Ducati.ms

ptourin · Jan 8th, 2012, 6:35 pm

I pulled the pump out of my tank today - pretty straightforward if a bit messy. It looks like I've got the stock filter, and the green o-ring still had some blue assembly lube around it that apparently wasn't fuel-soluble. No rust - a little bit of particulate junk in the gas but pretty clean all in all - I emptied the tank entirely and cleaned the junk out.

I have a few questions about the rebuild and would appreciate any info...

1. I assume the lines that disintegrate are the ones into and out of the filter - so a single 12" length takes care of both. Which fitting has blown off for people? I'm surprised that a hose would blow loose if everything is in working order - I've used those clamps on vintage cars and you can really tighten them way down.

2. What about the 2 hoses that go up to the filler cap? Is it worth replacing them also, or don't they ever cause problems? Should I replace other hoses while I have it apart?

3. If I use a NAPA filter, do I just clamp it with the ridge centered in the plastic clamp assembly and adjust the hose lengths accordingly?

4. What is the cream-colored plastic unit in the clamp next to the filter? It's got a hose barb on top with nothing connected to it - just wondering what it does.

5. If I pull the filler cap and clean the tank, is there another gasket for the filler cap that I need to buy?

6. Anything else?......

Thanks - Pete

Rev. Dr. Moses P. Lester · Jan 8th, 2012, 7:10 pm

I did a NAPA filter on mine and used all the original hoses and clamps, it fit just fine. It doesn't have the same OD as the old filter so it doesn't fit quite the same way in its plastic holder/clamp, but if you angle it in there right, the clamp will hold it.

va duc · Jan 8th, 2012, 7:28 pm

If the 2 vent lines should leak you will end up with a garage full of fuel, is it worth the risk? How old are those lines? Totally your call.
Most of the time its the fuel line that attaches to the outlet side of the pump that lets go, some folks will tell you to ty wrap the lines together( around the pump and fuel filter) to help keep them from separating under pressure. Did you remove the screen at the bottom of the fuel pump and clean it out? Also there is a small screen on the fuel pump inlet that should be cleaned. Good luck!

stryder · Jan 8th, 2012, 8:35 pm

Quote:

Originally Posted by ptourin

...

2. What about the 2 hoses that go up to the filler cap? Is it worth replacing them also, or don't they ever cause problems?

afaik, they are not under pressure like all the other hoses, so if they pass visual inspection you may be okat, but how old are they?

Quote:

Should I replace other hoses while I have it apart?

Yes.

Quote:

4. What is the cream-colored plastic unit in the clamp next to the filter? It's got a hose barb on top with nothing connected to it - just wondering what it does.

Air separator iirc. Removes air bubbles from fuel before being pumped to injectors to avoid lean conditions/detonation afaik.

Quote:

6. Anything else?......

Before you remount the tank, pour some gas into to check for leaks.

ptourin · Jan 9th, 2012, 5:40 am

Yeah - I especially like the "anything else"! I'm assuming everything in there is '98, so I'm thinking of replacing all the hoses. Expensive, that fuel-rated stuff! What about the other small-diameter hoses? - is there a substitute for those like for the large hose?

tonered · Jan 9th, 2012, 10:13 am

The lack of a real burr or bulb on the fuel pump nipple caused me a lot of trouble. I now just crank the hell out of the clamps. All the other are easy.

If you have an emissions canister still and the vent lines drop or split, then I believe you will have a running issue also. I'd replace them.

Have a good one.

ptourin · Jan 9th, 2012, 11:16 am

What's the deal with the emissions cannister? Where would I find it, if it's on the bike? I don't know anything about them - but there's a whole lot about this bike that I'm learning fast...

Stick · Jan 9th, 2012, 2:26 pm

1998 does not have a carbon canister. On the newer ST's (2000 + ??) it's under the LH mid fairing, via a special bracket (1998 does not have that bracket, either). So basically the older bikes vent off gas fumes to the atmosphere, the newer ones with the emmission canister vents tank fumes thru the activated carbon element. Very similar to carbon canisters on autos.

When you drive the vehicle, the fumes that were absorbed into the activated carbon are allowed to be sucked in to, and burnt off thru the intake manifolds (like when you de-cellerate--you have high intake vacuum...). This essentially "regenerates" the activated carbon element, and it's ready again when you park the bike.

tonered · Jan 9th, 2012, 2:30 pm

Oops. Sorry about that.

Have a good one.

Stick · Jan 9th, 2012, 3:22 pm

Tony, No Problemo! I guess it's one of the benefits of having put 53,000 miles on my ST2. I tend to notice the similarities and the subtle differences thru the years. Now I have 30K on my ST4s, and it's still pure love. Especially if I jump off the "old iron" and back to the ST4s. Wow, tons of refinement/power/handling, etc.