I have just hooked the carbs back up off the bike and the flooding has stopped,i turned the carbs 90 degrees foward and 90 back..no flooding,i had to undo the drain to make sure,i think i solved the problem with fresh drain and overflow lines.
Clamp them in the vice at the right angle and do a pressure test...........?? I can't see that new drain and overflow pipes would make any difference........
If you have no luck after AL's and others suggestions and assuming both carbs sitting at the std angle, I can only add 2 other possibilities which can happen. *On later Mikunis the overflow circuit is combined with the bowl drain facility and if the tapered bowl drain screws are overtightened (and it's very easy to do) the seat splits and allows fuel to exit through the drain hole which you could think was the needle valve seat weeping from the float chamber. The only other thing I can think of that hasn't been covered is when a deposit forms on not only the needle black viton face but also on the internal perimeter of the tapered seat (that AL has shown so clearly in post #10, lower picture) and the seat itself of course. Strangely i've never had it happen on all the Mikuni-equipped bikes i've had but had it happen on a pair of Keihins on a Kawasaki and the symptoms were similar to what you describe - baffling. I've never had this happen with fuel when lead was standard - these deposits were just like calcium and could not be removed with carb cleaner or lighter fuel etc and I had to make a tool from a biro and actually grind it away with cutting compound before the needle valves would stop weeping (you could scratch it off the needle tips with your nail with persistence) and it took me several attempts as I couldn't believe it was happening. the bike stood for 6 months after id MOT'd it and yes, you guessed it - I had to do it again.. I've always wondered why it never happens to me with the Mikuni's and all I can think of is that I won't use Supermarket fuel on Ducatis even if it is 99 octane because it has other chemicals than say Shell (apparently). *not applicable as I can see from picture you added while I was typing that you have earlier type with separate drains for bowl and overflow.
Thanks for that bit, Chris........I noticed the 'link' between the two circuits when I had the trouble with mine and even checked the drain screw seats having seen the stick up bit of brass tube in the float bowl......I didn't know the seats could split easily, though....... Dead right about fuel deposits.........I only use Shell or BP in mine (the car runs on what it gets) and, oddly or subconciously I think I have always used Shell in previous bikes.........(Never Esso...........I used to do work on Esso sites). And when that deposit gets into the pilot circuit and sealed gallery, try getting it out of there!!
. joke AL....a bit of crossed wires,i hooked the carbs back to the fuel line while off the bike set them at roughly the right angle with a angle finder....turned on the ignition and no leak,i was tilting the carbs back and forth trying to make them flood,but they didnt,i unscrewed the drain just to che k they had fuel in them which there was,also when i turned the key off an removed the fuel pipe there was still pressure in the pipe so i guess problem could be solved,dont no wot the residue was i the jug,it was separated from the fuel but didnt look like water,it looked oily but it didnt mix,any thoughts??
The screw seats on such a shallow taper that it's hard to sense when it's fully tightened I guess - you never bought a pair to find some petrol-proof sealer applied to the cracks inside? It took me a while to work it out myself because the leak caused by cracking the body is an internal leak and if you weren't aware of the common circuit you would just keep going back to fixing the needle valve weeping which would be working perfectly ok.
thanks for the tips,carb wise everything seems ok,it started first push of the button,i can have the bodywork off and the carbs off and stripped quicker than Slick Bass could do it,cheers.
