Though I might as well change the fuel filter in my '94 750SS, being furloughed an' all. So I have a couple of questions before I get round to it regarding the filler cap assembly seals. I see from other posts once the actual filler cap is removed, (by removing the cap head screws) & you then remove the grub screws around the inner edge of the plate, that plate should just pull out. But it is more often than not very tight & quite a bit of force is need to get it out ? There seems to be two seals, (according to the Haynes manual, my official Ducati manual doesn't even mention the fuel filter anywhere or the procedure to change it !!). The one around that plate to seal it to the edge of the actual fuel tank opening & a large diameter O-ring that seals that plate to the tank to stop fuel leaking out. I'm guessing the "weather" seal is only available from Ducati, but it seems that the large diameter O-ring in obtainable from other sources & much cheaper too. Does anyone know if that O-ring is the same for other models, i.e. this part https://www.polymax.co.uk/o-ring-117-07mm-id-x-3-53mm-cs-fkm-viton-75-sha that I saw in another thread on this forum. When I've tried searching Ducati dealers for spare part numbers they only seem to list models going back to around 2001 ish & my bike is 1994.
You are correct on pretty much all of what youve said. The easy bit is getting the cap off. The hard bit is getting the actual filler ring out. The metal ring of the tank gets corroded and the seal is tight so they can be a nightmare to remove. Once thats out though I would replace the O ring and the lip seal, if it's dry and cracked. On install, I use grease around the O ring. The lip seal is tricky to get on. I put the flange in most of the way then put the lip seal in place before pushing the ring in, if that makes sense. I think I have a spare OE O ring I could measure for you? Im 99 percent sure its VITON too. Ian
Cheers Ian, if you could measure it with a vernier that would be great, but it might be a bit difficult to get an accurate measurement with a loose O-ring as they, by nature, are easily distorted. You should be able to get an accurate thickness measurement though, but the internal & external measurements might be tricky. I do know the same O-ring fits the similar era, ('94) 916, 851, 888 & Monster models so if anybody has one of those that they know the measurements of that would help. I do have a Ducati part number, 88640111A, if that helps anybody. Also, I've seen on pictures of a similar O-ring in a plastic bag it had the dimensions printed on the label too. So far though I've been unable to match the Ductai part number to any dimensions.
There are some blind threaded holes in the filler ring - I think they are M5. I screwed some pan head screws into them and made a protective pad to rest on the tank top. With a small crow bar it is possible to catch the head of the screw and lever the casting up out of the tank. Go from one screw to the next lifting it a mm at a time until it lifts out. The O ring is easy to fit but refitting the black weather seal is a tricky job. When mine arrived I assumed it was the wrong part because it was so small. MotoRapido stock both seals.
Seals arrived the following day, excellent service from Moto Rapido Below are the two seals, the green O-ring & black weather seal, (on top of the filler cap showing the size difference). Obviously the weather seal, between the filler cap & tank, is going to be less easy to fit judging by it's size !! I can see what people mean now when they say it can be awkward ! Part numbers for the two seals are, 88640111A for the green O-ring & 79110151A for the weather seal. I'm guessing these parts will be the same for similar year 600's & 900's. I'll also measure the O-ring groove in the filler body when I get it out, it's not really possible to get an accurate diameter measurement of this large diameter O-ring when it's loose as it just moves too much. The thickness measures 3.5mm according to my digital vernier.
re: weather seal, i've never seen or needed to fit a new one, it does surprise me that the one you've received is that much smaller in diameter.
To be honest, I would certainly replace the green O-ring, but if the weather seal looks OK when I take it off I'll most likely refit it & keep the new one as a spare.
Well, boredom got the better of me again today & I thought it about time I replaced the fuel filter in my 750SS tank. I've had the bike from new & I'm embarrased to say I've never replaced it before. Removed the cap head screws securing the filler cap in place, realised you didn't need to remove the two screws at the "10 to" & "10 past" positions, (they are only very short & it's only the other three that secure the filler cap in place). Sure I had read about these screws too, after I'd removed them. This revealed the eight grub screws securing the filler neck in place. Gave the area a clean out & then removed these eight grub screws & lifted out the filler neck. I'd read others posts about how hard it was to lift out the filler neck, but mine came out very easy really, just put my fingers in the filler hole & pulled it out with a bit of rocking ! I was a bit shocked to say the least !! Just put a bit of kitchen roll in the neck too to keep as much rubbish out of the tank as possible. Should have put this in place before I dropped my 5mm Allen key in the tank ! Removed & put to one side to get at the filter & pump. Access to the filter & pump is now much easier. I found the hardest part of the job was getting my hand in & levering the fuel pump body out of the two spring clips that hold it in position. New fuel filter connected, (the correct way round !) & a new O-ring fitted to the filler collar & it was then re-inserted into the opening in the fuel tank. I applied some silicone grease to the O-ring & some red rubber grease to the groove in the tank opening where the points of the grub screws locate. The reason for the red grease is it makes it easier to see if the collar is pushed down far enough so that the grub screws correctly. You can look down the threaded grub screw holes & see the ring of red grease, indicating the filler neck is in the correct position. When pushing the filler neck back in position you need to ensure it's correctly orientated so that the filler cap doesn't end up at some odd angle !! Ideally I should have marked the filler neck & tank before removing it, but I forgot ! With the filler neck almost in the correct position now is the best time to refit the weather seal. I had a plastic scraper that I use for removing sealant on aircraft, which was perfect for this job, so I didn't damage the paint around filler neck. Before re-fitting the grub screws I just checked the pump was working, the new fuel filter was filling, the return pipe was returning fuel to the tank & there were no leaks in the pipes I had disturbed. When re-fitting the eight grub screws I found it best to tighten the first four at quarter positions, that way when you come to tighten the other four they must be in the correct positions. That is providing you checked the first four grub screws for being in the correct positions of course ! With the filler collar in place Job done ! Cut open the old fuel filter, (which I think may well be the original) to have a look how dirty it was. Also, lifted out these bits of crud that were in the bottom of the tank, right at the back, in the two corners. You can actually see these bits of crud in the tank in the photo above showing the fuel pump clips.
Thanks for posting that photograph,i'll look into mine in the new year regarding rust etc,p.s i hope you've treated that metal area with something.
To be honest "no" I dislike any sort of gloop in my fuel tanks unless really absolutely necessary. There is a little bit of very light surface rust in a few spots & it's been like that for years. I've had the bike from new I don't really see that it will be a problem, certainly not for me in my life. I always now keep my bikes with a full fuel tank when they are not being used so that minimises the area where moistue can get in.
You're the benchmark from now on with that statement,..and yes i do leave fuel in the tanks as well over the winter period except that plastic thing on the PS.
My Daytona has a placcy tank too. I fill my bikes with Esso unleaded supreme+ fuel as around here, (Cheshire) it is ethanol free & it seems to be the ethanol that does the damage, certainly to plastic tanks anyway, from what I understand. In areas including Devon, Cornwall, Teeside area & Scotland there is ethanol in Esso fuels. Quite why those areas are different I have no idea.
(just put my fingers in the filler hole & pulled it out with a bit of rocking ! I was a bit shocked to say the least !!) jammy git you got away lightly with that one mine was a royal pain in the *** to remove lol getting back in was just as much fun great job nice pics hopefully you will notice a bit of difference in running with a fresh filter
