Hi guys, I have just bought a 600ss in need of some 'attention' to bring it back to health.. I lifted the tank to find all the fuel pipes off and I need some help to find out where they go again.. There is a pipe with a 'y'section which I think goes of the fuel tap and the return line and the other end to the fuel supply on the carb, ( the one with the little white filter). The puzzle is though, that the other union on the carb that I thought was a fuel return is plumbed into the plastic breather on the lhs of the frame. Then that leaves the third pipe on the tank.. Please someone help as I think I'm losing the plot.. Thanks...
with tank up - left hand is fuel supply (with knurled on/off thumbscrew), middle is return and right hand is the 'drain'
If your 600 is like my 750; as Chris said, under the tank is the tap / flow pipe; the return flow; and the drain from the filler cap recess. The flow pipe does what you say and has a Y in it.....feeds the carbs and which sends fuel back along the return pipe. The carbs fill via the tee-piece between the carbs...the tee-piece has the tiny filter in it. The tank breather comes off the top off the tank and connects to the little ally breather valve (arrow faces forward, away from the tank) and then it goes down the yoke / headstock centre and hangs via a clip (or two) just below the clutch casing. You should also find two slightly larger bore pipes from the carbs which are pushed into a breather box on the left side of the bike.....some people do away with them......I haven't....... ....and I have been assured by a Ducati trained mechanic (albeit he is now retired and may have got his wires crossed) that the breather box acts a flame trap.. AL
Thanks for the replies. Makes more sense now, as the drain is from the filler.. should have looked at the pipework inside the tank, that might have given me a clue.. d'oh. Anyway, on the carbs immediately above the fuel feed, there is another tee piece with a pipe going also to one of the breather boxes on the lhs.. Is this correct, as I thought it was an overflow from the floatbowls.. Indeed it is open to the floatbowls, but if someone could confirm or correct, I would appreciate it. Thanks again for the help, good information. Btw, what could I do with a very rusty tank that isn't leaking... yet??
Sorry, forgot that pipe.....It's a breather for the float bowls....air gets pushed out as they fill up.....it connects to a small spigot on the flame trap breather box.... and of course, I forgot to mention the two thin plastic float bowl drains / overflows held on with spring clips. Can't / won't advise on rusty tank....too many options and mine is already decided. AL
Excellent, thanks for that, I can get the carbs sorted and back on ready for a clean tank if I can sort it.. BTW, would anyone know roughly yhe settings for the jets at the bottoms of the carbs. They were really stuck in my bike and with getting them loosened up, i think that they were around 1 1/8 turns from fully home... Would that sound about right??
if bike is totally standard then it's more like 2 to 3 turns out but it's worth trying 'your' setting to start with as there may have been a good reason for it.
May I suggest that before you reassemble, you tell us what size the main jet is and post a pic of the spring and needle........just making sure you don't have a Dynojet kit fitted, so we can give you OEM/stock settings. AL
Hi there, I had a look at the jet this evening and the main Jet loks like a '70' and has the little square shape on the jet.. I think that this means it is a genuine part, i think.. Anyway, the needle has the same square mark and is a '5CJ1'. It all looks fairly standard, but for a set of Restrictor plates when I took the Carbs and manifold rubbers off.. Perhaps it needed some modification when these were fitted..
The 70 isn't the Main jet....it should be 132.5......However, it would appear from what you have found that the parts are OEM/Stock (the square mark). Not sure about the restrictior plates...where were these fitted, exactly? AL
as AL says above re: jets. I'm guessing that the bike was restricted to 33 brake then (two large dia washers?) and this would explain why idle mixture screws were only opened 1 and 1/8.
Oops, my mistake.. Main jet is indeed 132.5.. The carbs have been sitting for quite a while with stale fuel and thus have a good coating of varnish.. Hopefully a combination of carb cleaner and ultrasonic and new gaskets and o -rings should make them feel a little better. They def wouldnt have worked too well.. The restrictor plate was fitted in the inlet tract just in the rubber mount and consists of a layered steel disc with an off-centre cut-out to restrict the air flow and fuel charge.. They will now remain on the bench or in the bin..
Chris can probably tell you if leaving the restrictors out will mean you need to re-jet...... ........the 132.5 and 70 jets are indeed for the UK market, so I am assuming that all 600s were restricted. I have here the Stage 1 & Stage 2 Dynojet kit instructions and specifications......interestingly the Stage 1 main jet sizes (two alternatives) are 124 or 128.... There is no mention of removing the restrictors, even though the instructions are specifically for the European models. ....However Dynojet measure their jet sizes by flow rate and not by dimension so there is no comparison between them and OEM jets. DJ also state that whether Stage 1 or 2, the pilot screws are 2.5 turns out. AL.
My feeling is that these were an aftermarket addition as there is a retailers stamp on the plates.. It is something like "Motorcyclecity" or something like that..
I think you are right as the only official Ducati restriction route was to fit a 'hand throttle rotation limiting' plate to the carb bodies as far as i'm aware. When 'washers' are fitted as restrictors all jets and needles are normally left alone on 'constant depression' type carbs such as ours so apart from confirming needle and needle jet sizes, above jets and carb set-up will be fine. MOO
