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Bit of a diiference between straight off the bike to the ultrasonic cleaned version! New service kit and float installed ready to go back on the bike.
Niow, I've made a real rookie error...I didnt photo everthing and as its been weeks since the carb was removed I forget how the fuel lines went. I think the Y has the 2 branchs facing towards the front of the bike both connect to the tank, single goes to carb?
2X green translucent pipes. 1 goes onto the tank and vents to air, there is another on on the tank and I dont know where it goes (RHS)
The carb had one black pipe running from LHS to "computer" module at rear and the fuel line...anything else? Ahhh, for photos

My carb only has one fuel line coming into it. The 'computer' one is a bit bizarre, what year is it? I'm sure my fuel line set up has been changed from stock but the main feed hose that runs from the fuel tap has a 'T' join in it mid way along and a hose runs off vertically back to the tank. That is the 'return' . beside that one on the bottom of the tank is your breather that goes to where ever its routed on your bike. I think the breather is the port nearest the middle of the bike and the return is the one on the outside but it is labeled on the bottom of the tank, poorly translated from Italian. Cant remember the exact words. Can take pics tonight if need be, gotta get to work!

The 2 brass nipples on either side of the manifold should be T'd together and routed to the ignition module . These are vacuum lines so the ignition unit knows manifold vacuum and can adjust whatev .
The T in the fuel line , wherever it is ......the idea is to reduce fuel pressure and by mucking round with the length and dia of the return line you can adjust the fuel pressure the carb receives. Some peeps fit a fuel pressure regulator.
The tank should have a fuel outlet , a breather and a return line . The breather has a tube on the inside that goes to the top of the tank .
I think the 2 vacuum ports are T'd together as 2 vacuum pulses are smoother than 1 , any how thats where I connect my vacuum gauges when I balance the carb . The ignition module can run with the hoses disconnected while the carb is balanced

How's this look. I wasn't going to post this
...but the T piece for the carbs vacuum line was amongst other bits and pieces and id forgotten all about it. Without your reply Mc tool I would have _ucked up royal. Thanks. Photos! I'll never forget to take photos again! 2 piece on each side of carb onto a pipe that runs back to the magnificent digiplex 2S by magnet marelli

The whole thing looks good

Interesting. Both those ports on the side of my carb are blocked off with machine screws that look kinda factory. I cant see in your photo where the other end of the hose goes to but there's no nipples or anything on either of my inlet manifolds. I wonder if this is why my bike runs rough when getting back on the gas?

Depends on the ignition . If you have the weber marelli box then you should have a vacuum line , but some bikes had Koukusan modules ( one for each cyl ) and they Dont have a vacuum line . I think some of the P750's had the Koukusan , my 97 SS did .
Kiwi , that "bit rough when getting back on the gas " is the whole reason why peeps have been fiddling with the fuel system on these weber equipped belt drives . I honestly think you will get more pleasure learning to "ride round " this issue ( ya just gotta stop this neutral throttle pissing about and give it a good nudge ) than you ever will trying to fix it .
I used to think Weber ....Itallian ... Ducati ......it should run like a Swiss clock ....but nah .
My friend married an Itallian girl .... man what a stroppy bitch ( she wouldnt last 5 mins in my house , way to furry too ) anyhow #uck , where was I , oh yeah I think the bikes are the same ........stroppy not hairy

Yeah I've got too used to perfectly mapped fuel injection. And if it's not perfectly mapped then I flash it till it is lol.
I'll persevere for a bit longer as it's become a long term project now, then failing that I'll try some Chinese flat slides haha.
One thing I have eliminated is the cutting back of the fuel delivery pressure. Didnt help, worse even.

Dunno if you noticed but down the page a bit from the chinese FCR's there is a reasonable looking jet kit .
One of the things some peeps thought helped was 4.5 aux venturies ( Have you read 'Weberology " search here for it ) but they were not available apparently ( lots of peeps looked ) and then some dude piped up years later and say " oh yeah they are the same as maybe the IDA or IDF not sure exactly what he said , but anyhow they were and then I forgot about it . It was talked about here not that long ago ( few years ), and I dunno if it even worked .

It will either keep you awake , or put you to sleep

So off each side of the carb, into the T and then down the LHS of the bike into the box of tricks at the back. Bottom RH corner, that's the pipe connection

Ah OK, cheers for that. You got the more sophisticated model!

Kiwi Rider wrote: ↑Sun Oct 12, 2025 11:30 pm Ah OK, cheers for that. You got the more sophisticated model!

Ah , if your refering to the ignition I would rather have the Koukosan.