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That would be great Lelebebbel! I wont be able to do this until the weekend. I really appreciate it. Ive never worked in a gas tank.

Im also confused as to what parts I would need. Ill research a bunch. I know I need gas friendly hoses.

Thanks!
See my post for my buddy's ST4 in tank fuel hoses. The short answer is that if you have hose that is exposed to fuel both inside and out, woe unto thee if thou dost not use the correct hose.

https://www.ducati.ms/forums/241-tech-forum/720853-st4-tank-fuel-hose.html
 

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Discussion Starter #22
Once you have the gas cap assembly out the hole in the tank is surprisingly large, easy enough to put one hand in with a stubby short phillips or nut driver and unscrew the hoses clamps to yank the tiny pump out. You will see, I have old school cell phone chargers that are larger than the pump.

Clips? Um, thin "U" shaped pieces of metal that a round barrel shaped pump fit into with a mild amount of pressure?

See the loose rust flakes in the bottom of the tank looking like the rotting fender on your great grandads Model T discarded out in the south 40 acres of his farm? Yeah, you got some more work to do so see what you've got first before digging into what is involved in fixing that kind of problem. Spots of ugly rust on the walls of the tank are sadly not too unusual and eventually they will be a problem but that could be many thousands of miles down the road for you. If the bike has been ridden in the last five years, you likely have nothing to be concerned about. It is a very good sign that the previous owner put that external filter on, they knew what they were doing, and yes I currently have two filters on one bike and the other has no in tank filter anymore - just the external one I can easily see when it needs changed. They both have new pick up screens on the pumps.

So something seems to be clicking inside the tank, you have potential gas delivery symptoms - don't delay finding out the cause of that noise, those are not normal.
Yeah thanks, It wasn't happy and I wont drive it again until I over-haul the tank with new filters and hoses. If it happens after that, I will listen for the source of the clicking. I checked the battery connections and they are fine.

Do you know where the relay for the fuel pump is? I would like to check that fuse connection.

I have sourced the parts from Omaha no problems. Are the OEM stock fuel safe short hoses that connect the pump and filter ok from Omaha, or is there a better fuel safe hose I can buy?

Is there a cheaper alternative for the pump screen/filter?
 

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Discussion Starter #23

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There is no fuel pump relay on a carby. you have a main relay that is working or you would lose all power and a flasher for your turn signals.

This does not mean you are not having a power supply or ground issue but that would be easy to test.

A external filter is a good idea if you have a badly rusted tank but if not there should be little need for two filters. Just take the one out of the tank while you are in there and run something similar externally, as a fyi I have had some bikes not pass enough fuel with the type filter you have external.
 

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Discussion Starter #25
There is no fuel pump relay on a carby. you have a main relay that is working or you would lose all power and a flasher for your turn signals.

This does not mean you are not having a power supply or ground issue but that would be easy to test.

A external filter is a good idea if you have a badly rusted tank but if not there should be little need for two filters. Just take the one out of the tank while you are in there and run something similar externally, as a fyi I have had some bikes not pass enough fuel with the type filter you have external.
Ok, thanks Ducvet that sounds good. Ill take that one off first thing. The bike was running fine with it for a few weeks though. I picked up an OEM see thru filter for the inside, can I run that on the outside or is it a different I.D on the outside hoses?

The reason they put the outside filter on was because debris was causing the floats to stick open. The tank isn't bad but it was allowing debris in the carbs. Will the new OEM filter be enough to prevent the floats from sticking?
 

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If there is debris still in the carbs it will have to be cleaned out by removing them and replacing all the gaskets ie: rebuilding

If you take out the internal filter and replace it with hose, I would recommend looking at replacing the pickup "sock".

Put a larger generic see through inline filter (bigger than the one in the pic) after the Y connection outside of the tank. Watch it carefully to see if it becomes dirty in only a few hundred miles. A filter at least an inch in diameter and 2 1/2 inches long should work. You probably have 5/16" hose.

You may as well put a shut off valve there too and use it all the time since the previous owner has said the floats were sticking. The only permanent cure for that is rebuilding the carbs.
 

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The reason they put the outside filter on was because debris was causing the floats to stick open. The tank isn't bad but it was allowing debris in the carbs. Will the new OEM filter be enough to prevent the floats from sticking?
Have you removed the fuel filler cap and the carrier from the tank and had a good look around inside? I would think that if you were getting rust flakes into the the carbs, there must a) be a significant amount of rust inside the tank or b) the fuel quality sucked and debris was entering the tank from fuel up.

You'll have to pull the cap and carrier anyway since you're going to be replacing the fuel filter and the pump sock. Here are a couple of pics to help you visualize what you'll be looking at:


^^Cap and cap carrier removed^^^



^^^ Looking down the line, the filter, then the pump and then the pump sock is visible at the end of that line of parts.


^^Cap carrier and weather seal^^



^^Pump and filter removed^^



^^Pump and pick up sock ^^

Once you remove the cap carrier you have a generous hole to work with. Not gonna get both hands in there but definitely enough room to do the work needed. Hope the images are helpful......sean
 

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Discussion Starter #28
If there is debris still in the carbs it will have to be cleaned out by removing them and replacing all the gaskets ie: rebuilding

If you take out the internal filter and replace it with hose, I would recommend looking at replacing the pickup "sock".

Put a larger generic see through inline filter (bigger than the one in the pic) after the Y connection outside of the tank. Watch it carefully to see if it becomes dirty in only a few hundred miles. A filter at least an inch in diameter and 2 1/2 inches long should work. You probably have 5/16" hose.

You may as well put a shut off valve there too and use it all the time since the previous owner has said the floats were sticking. The only permanent cure for that is rebuilding the carbs.
Ok, sounds good. So far it hasn't leaked since Ive purchased it. Yeah they had problems and had to clean out the carbs. A shut off valve sounds like a great idea.

Yeah Omaha has an OEM sock Ill get for sure.

Do you mean put the external larger filter where the little one is now, or after both hoses join at the Y? Is the filter in the wrong spot right now, only conditioning one line? That has me confused.

You guys are super patient with a noob mechanic and Ducati owner like myself. I teach at School of Rock so I get it, but thanks again for the help. The students love the bike BTW.
 

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Discussion Starter #29
Have you removed the fuel filler cap and the carrier from the tank and had a good look around inside? I would think that if you were getting rust flakes into the the carbs, there must a) be a significant amount of rust inside the tank or b) the fuel quality sucked and debris was entering the tank from fuel up.

You'll have to pull the cap and carrier anyway since you're going to be replacing the fuel filter and the pump sock. Here are a couple of pics to help you visualize what you'll be looking at:


^^Cap and cap carrier removed^^^



^^^ Looking down the line, the filter, then the pump and then the pump sock is visible at the end of that line of parts.


^^Cap carrier and weather seal^^



^^Pump and filter removed^^



^^Pump and pick up sock ^^

Once you remove the cap carrier you have a generous hole to work with. Not gonna get both hands in there but definitely enough room to do the work needed. Hope the images are helpful......sean
Thanks Sean for the great pics and help. Holy crap is that tank clean inside. Now I really don't want to really look at my tank. It looks nowhere near as nice as yours. This is probably going to cost me a bunch of cash and springtime riding now that I compare the two! That's funny, its the first thing I read about before I bought my bike...is how bad these old tanks can be, in any brand of motorcycle..and now here I am.

Where did you get the sock and pump? Everything looks brand new. The sock alone at Omaha is $48.60!

I will know more Sat. Ill take pics and cringe when I show you guys.
 

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That sock is fairly generic, I got mine for 8 bucks at NAPA, forgot what diameter it needs to be but take your old one in with you. Ducati didn't make that sock, they bought it on the spot market nothing special about it. Test your pump after you clean it off by hooking it up to 12v, don't let it run very long. I suspect it is just fine, that external filter is constrictive enough to cause the pump to struggle, especially if the sock is clogged.

https://www.ducati.ms/forums/57-supersport/143625-inexpensive-alternative-parts-list.html

I would put the filter after the Y connector, be careful the Y is only plastic and breaks easily.

Cleaning the gas tank is smelly, but not too bad and certainly not expensive. Here is a video
 

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Discussion Starter #31 (Edited)
That sock is fairly generic, I got mine for 8 bucks at NAPA, forgot what diameter it needs to be but take your old one in with you. Ducati didn't make that sock, they bought it on the spot market nothing special about it. Test your pump after you clean it off by hooking it up to 12v, don't let it run very long. I suspect it is just fine, that external filter is constrictive enough to cause the pump to struggle, especially if the sock is clogged.

https://www.ducati.ms/forums/57-supersport/143625-inexpensive-alternative-parts-list.html

I would put the filter after the Y connector, be careful the Y is only plastic and breaks easily.

Cleaning the gas tank is smelly, but not too bad and certainly not expensive. Here is a video
https://www.youtube.com/watch?v=dT3vUX7vUGs
Thanks RockAZ, That parts list is awesome. The tank video is a huge relief and right down my alley (I used to paint helicopters for a living...it could get messy). I am looking forward to finding out what is going on tomorrow.

I am having flashbacks to the 70's as a kid hearing about old tanks doing this to the carbys back then.

Once again you, Ducvet, Iwannaduc and everyone on here, have really helped me feel better about fixing this. Man how did we make it 20 years ago without the net? If I had this happen without a forum like this, I would have been forced to go to a dealership, and been pretty bummed. I really love the bike, It runs and handles great under normal fuel conditions. I really want a 916 next.
 

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You can find a post on this site from me regarding how I used non-toxic Metal Rescue to remove rust from the interior of my fuel tank. It worked really well for me and isn't a non-reversible process like coating the tank. If the tank is rusting to the point where it might perforate the Metal Rescue may not be the best solution.
 

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You can find a post on this site from me regarding how I used non-toxic Metal Rescue to remove rust from the interior of my fuel tank. It worked really well for me and isn't a non-reversible process like coating the tank. If the tank is rusting to the point where it might perforate the Metal Rescue may not be the best solution.
I'm in denial about this issue on my project bike, but I should go through that thread. I'm sure I'll need it.
 

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shot-peening, aka sandblasting is another alternative, especially if it is either really bad or just a few bits of rust around the seams. I like the creme route if you are going to keep the bike forever and you are likely to paint the tank afterwards anyway.
 

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This guy will strip and coat the inside of the tank w/o harming the paint. I have had it done on two bikes, including my all orig MHR Mille that was starting to clog filters and jets. It still looks great after 5-6 years. Not cheap.

Motorcycle Fuel Tank Services
 

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You can find a post on this site from me regarding how I used non-toxic Metal Rescue to remove rust from the interior of my fuel tank. It worked really well for me and isn't a non-reversible process like coating the tank. If the tank is rusting to the point where it might perforate the Metal Rescue may not be the best solution.
On my Lambretta project I use one part molasses to ten parts water.

It takes a few days but works well.
Here is some techo info if you are interested.
https://www.answers.com/Q/Why_does_molasses_remove_rust#slide=1

Should you choose the molasses route, you probably only need to have a few inches of the liquid to cover the rust.
 

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Discussion Starter #37
How do I remove the carrier? I have the grubs completely out and its frozen in there.
 

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Discussion Starter #39
Pull straight up, not always easy so make sure to protect around the top of the tank or you may smack the paint with the insert. It can be hard but is done every time I have to change fuel injected fuel filters.



Thanks Ducvet,

I cant get it. Ive pulled up on it so hard I feel like Im going to pick the bike up. Its not acting like its remotely moving. Im afraid of ruining the tank even with towels taped around it, I would smack it back down for sure with the extreme force Im using (both hands or one).

When I tried to drain the fuel by turning the key on, it only trickled out of the M hose with the pump running fine. I had to siphon it. Is this an indicator, shouldn't it come out quicker?

The tank actually looks pretty good compared to a trashed one. Small spot areas of discolor but that's it. I siphoned from the rear where the sock is and saw nothing coming out at least. The tiny filter I removed had nothing in either but is a bit restrictive when you blow through it.
 

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"When I tried to drain the fuel by turning the key on, it only trickled out of the M hose with the pump running fine. I had to siphon it. Is this an indicator, shouldn't it come out quicker?"

Absolutely should come out quicker, draining the whole full tank in less than a minute. Both the internal filter and sock are suspect, I bet the pump is fine.
 
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