Evening chaps The drain pipe from the petrol tank filler assembly (92 900SS) has started to exude a tiny amount of petrol over the last couple of weeks, which is a bit of a suprise as the outlet has been blocked solid for years. My first experiment was to blow/suck up the from the lower end of the pipe and found it still blocked solid! I effected a cunning cure by doubling the end of the pipe which at least stopped petrol from dripping out onto floor/tyre etc. I've just drained the tank, removed the filler cap surround and inspected the inside of the tank. There's the usual patches of surface rust at the rear lower (which I'll give a coat of Trustan in the morning, more in hope than expectation) but nothing alarming. I've both blown & sucked the tube from the filler to the outlet and there's no sign of any air movement at all .... if I suck and then place my tongue over the end the vacuum sticks my tongue to the tube. So, how is fuel getting from inside the tank into the drain hose? The outlet appears to be blocked & airtight and the internal hose appears undamaged. Has anyone taken the tank outlets appart? The only clue I have is that the spigot the internal hose pushes over seems to have a little movement ..... I've not yet removed the hose as none of my screwdrivers will get onto the hoseclip, I need to buy a nice little dumpy number. My current favorite plan is to reassemble everything & plug the bottom of the drain hose until the weather stops play and then have a more serious go at a proper fix ...... but if anyone has had this problem and can suggest a fix then please speak up! Cheers Grunt ps why do they do this sort of shit just when you finally (after 21 years) get them going, handling and stopping like they should have done when they came out of the factory in the first place?
Which one do you mean is the drain hose? If you mean the one immediately in the aluminium unit of the filler cap and the little recessed hole in it, which drains when you overfill the tank, then has the actual seal to the lift up part of the filler cap failed.......? That little hole and the internal pipe and spigot were blocked solid on mine and it took quite a bit of work with thick strimmer cable to clear it. But the drain is basically a piece of hose from the cap to the spigot inside and then the long length connects to the outside of the spigot to drain below the bike.........That hose could have broken down a bit allowing petrol to seep into it or the hose clip isn't tight enough. AL
Aha, that was my first theory. Sadly not, as I've tested that hose by sucking and blowing. I'm sure if the hose was compromised my tongue wouldn't have been sucked into it by the vacuum. Current theory is that the weld/braze between the lower spigot and the floor of the tank is cracking. Can't see that yet as hose is still secured on spigot.
Looking at several photos of the inside and outside of a tank, I think the spigot pipe is continuous through the tank floor, so unless the pipe is actually holed, I can't see that the weld cracking would let petrol into the spigot and you would have a leaking tank instead. You should be able to easily blow right through the drain arrangement from just under the filler cap to the end of the hose below the bike. AL
a real head scratcher, have you watched and seen a drip appear at the end of this drain tube or is there a chance it's running down the outside of the tube and exiting from somewhere else? As this is defying all normal reasoning sounds like you will have to dig deep. Might be worth blowing tube and get someone to look inside tank for bubbles maybe just to confirm no splits within tank void as the hose might be collapsing and sealing when you suck.
Hi Chris I'm pretty(very!) sure that the hose in the tank is uncompromised. The evidence of fuel appearing from the extenal hose points to the origin of the fuel to be from the inside of the tank outlet ie the fuel collects inside the hose when I block the end up. I've still not removed the internal hose from the tank base spigot (where any drained fuel would exit) due to lack of suitable screwdriver but trgaically I reckon I can feel a slight lack of resistance if I apply sideways pressure to said spigot. In other words I think the spigot may be cracking. As the whole cap drain system has been blocked solid for years with no problems (just don't overfill the thing) I'm probably just going to stuff the external spigot (where the external hose pushes on) with epoxy resin and put it all back together. You never know ... tomorrow the sun may shine and I'd hate the bike to be garage bound.
I would not be absolutely sure about the uncompromised integrity of the internal hose, although I assume it's the original which is positive. I say this because a couple of years back I had to seal the tank on my 900SSie (using POR15 kit as widely discussed) and when I came to put it back together I decided that I would replace the two internal breather hoses, partly because they were more than 10 years old and partly because they had torn a little at the ends when I removed them from the spigots during the tank rebuild. Initially I gave little thought to this and simply bought a length of fuel hose, thinking "the inside and outside must be the same material so it makes no difference as far as being petrol-resistant". Then I found that the hose I had bought for very little from a bike shop was a bit too stiff to fit easily over the spigots, so I bought some more, after looking closely at dimensions and spec, from an eBay seller (Advanced Fluid Solutions I think) and was pleased to find that this fitted well. I had some reservations having read things by then about "submersible high pressure hose" for injection systems, and so I was not completely surprised when some weeks later I noticed a very small fuel leakage from the breather. It was infuriating to find that the tubes had in some way become porous, but they had not disintegrated or visibly punctured - they had become rather more flexible than the spare tubing which had not experienced the petrol treatment though. It turned out to be very difficult to track down any "submersible" tubing of the right dimensions. In the end AFS sold me some significantly thicker tube of the right spec which they had ordered in specially due to some recent demands for it - I had to use small pieces of the original tube over the spigots to make this new tubing fit, but it seems to have done the job. Clearly I would have had less trouble if I had bought new tubing from Ducatii, but I had read somewhere that it is staggeringly expensive (much more than I paid in total for all three lengths of hose that I ended up with).
Right, thought that there might be a problem with sourcing hose locally. As it happens I've just removed the inner hose from the lower spigot ..... well, I slackened the hose clip and the hose came away complete with the "bell" section of the spigot and leaving the lower few millimetres still attatched to the rest of the spigot. The spigot is completely blocked with rust which is fine by me but I can't imagine how even the tiny drible of petrol that has egressed managed to find its way through. Neither can I work out how the hose remained air-tight! Anyway I've trimmed the end of the hose and clamped it back onto the remains of the spigot. I've not reassembled the tank yet 'coss I've given the (slightly) rusty patches a brush over with Trustan and I'd like to give it a wipe with a wet rag after 24 hours reacting. Still deciding whether to fill the spigot exit with some chemical metal just to be on the safe side ..... think I will, I just hate that sort of distraction when I should be deciding how best to overtake the latest 200hp missile getting in the way on the Sunday Circuit.
Anyone got a genuine Ducati workshop manual which might clarify the connections/fuel system. I have one for the 2002- models which is pretty comprehensive.
The Carbed SS ones are quite simple when you look inside and outside the tank........ In the case of the OP, if that spigot itself has rusted and is breaking down, which is what it sounds like now, the easiest way out is to remove it all together; clean up the hole nicely to take a threaded spigoted union with nuts and neoprene sealing washers both sides. AL
Spot on, mate. The inner spigot on floor of tank is rusted internally to the point of no-flow (except for a minor seepage, obviously) and swelling enough to rupture the hose. Current state of play is thus: internal hose trimmed and replaced (why? .. who knows?), lower spigot exit sealed, upper drain hole (in tank filler cap base) temporarily sealed to stop any water ingress in case internal hose holes again. Slight problem with your otherwise elegant solution is that the outside of the lower drain spigot is quite a complicated looking right angled pillar thingy ... must be 10mm in diameter. Anyway, I now intend to just check for pooling water in the filler assembly after wet rides or washing the thing (not too regular occurencies, to be honest) and concentrate on the finer things in life. Many thanks for all the interest and useful thoughts. I think decent forums are one of the better things about the web.
If you couldn't find a suitable union, it wouldn't be too difficult to make one.......Say, a 12 - 15mm dia brass threaded bolt and suitable nuts & washers, drill the bolt 8 - 10 mm dia hole after having cut it the right length.........then bend a length of 8 - 10mm dia copper tube (I have got a coil of it here) at right angles, insert the straight leg into the bolt after having given it a damn good clean with abrasive cloth; then blow torch; flux and solder...... But for added info....see below (not mine I hasten to add).......I reckon the return spigot is 10mm dia (the hose is 8mm bore) so guessing, the drain is 8mm diameter.
I wonder if there are any specialist fabricators who could just weld in a new section, Classic Berk magazine might be useful in rooting someone out?
As you can see from this pic (if you squint enough) the outlets on my tank are a tad more complicated than the ones in the pics above. I'm not entirely sure how I would remove them (it) without making a rather large hole in the tank floor.
Well you can certainly drill the drain spigot out easily, because the floor of the tank looks as though it is reinforced around the spigot and I'm sure we could find a source for a suitable 'bolt - in union'.... AL
If this is as I think, (the pipe under the frame) had this many times! my only cure was not to overfill the tank? crap way to have to do things? but after filling up with anything over a tenner, it just flows out under the bike? still cant find another cure :-(
