Fuel Return Hose

[Colonial Boy]

I put my 906 back together after its repaint and tyre mods (which took about 4-5 months) and it didn't fire. Got spark, and fuel at the tap, so it's off with the tank and the airbox - and the carb is bone dry
The pump is pumping fuel up to the Y connection and then straight back to the tank via the return. The hose to the carb is not blocked and the float valve is not stuck.
There are two pipes poking out of the underside of the tank - I connected the return line to the front one, and the breather (I assume) to the rear. Have I mixed them up?
It seems to me that for the system to work there must be a pressure regulator in the return line - is it in the tank?
Sorry if this has been asked before. I had a look at the Weberology topic to see if the answer was there.
The bike ran fine before I laid it up so I put some fuel in the carby bowl and put the top back on and it fired instantly and ran well.

Hope someone can enlighten me on what I've done wrong!

Cheers, CB

[Duc906]

I put my 906 back together after its repaint and tyre mods (which took about 4-5 months) and it didn't fire. Got spark, and fuel at the tap, so it's off with the tank and the airbox - and the carb is bone dry
The pump is pumping fuel up to the Y connection and then straight back to the tank via the return. The hose to the carb is not blocked and the float valve is not stuck.
There are two pipes poking out of the underside of the tank - I connected the return line to the front one, and the breather (I assume) to the rear. Have I mixed them up?
It seems to me that for the system to work there must be a pressure regulator in the return line - is it in the tank?
Sorry if this has been asked before. I had a look at the Weberology topic to see if the answer was there.
The bike ran fine before I laid it up so I put some fuel in the carby bowl and put the top back on and it fired instantly and ran well.

Hope someone can enlighten me on what I've done wrong!

Cheers, CB

Hey CB, The return hose should have a jet in it to control the fuel pressure.I think it goes to the front pipe on the tank

[paso750]

I connected the return line to the front one, and the breather (I assume) to the rear. Have I mixed them up?

yes, you did. Look at the user manual p.11.

Ken, what size is that jet ?

[Duc906]

Ken, what size is that jet ?

The jet was factory fitted and it has 60 stamped on it.It looks like a dellorto carby jet.
I'm off to the shed to swap the return/overflow hoses over.

[Colonial Boy]

yes, you did. Look at the user manual p.11.

Thanks paso750. I am unable to download the manual. I will connect it to the rear pipe tomorrow.

Cheers, CB

[Colonial Boy]

Hey CB, The return hose should have a jet in it to control the fuel pressure.

Thanks for the info & photos Ken. I will check the jet is in place and hook it up with some new hoses. Fingers crossed!

Cheers, CB

[paso750]

if the links in my downloads thread didn`t seem to work then just hit the refresh button of your browser otherwise try here http://ducatipaso.org/docs/906/manuals/

[higgy]

[ducapaso]

I am not sure about (I'm a 750 owner) but fuel return has not both "Y pipe" and double pin under the tank. There is something I don't understand.
Return line should go to directly to the tank from the weber if you have the double pin.
Otherwise to the Y pipe located under the petcock, with the 0,60 jet in the connection.
You can also verify the intgrity of the small net filter inside the weber inlet, removing the 19mm brass nut.
If nothing works, stop the fuel return and leave the electric pump work for a while, to push the fuel inside the carb.
If the going get hard, pull away the airbox and spray some fuel inside the trhorttle bodies... just for a while and try start the engine

[Colonial Boy]

if the links in my downloads thread didn`t seem to work then just hit the refresh button of your browser otherwise try here http://ducatipaso.org/docs/906/manuals/

Thanks - the problem is in my very slow dial-up download speed, not your files.

CB

[Colonial Boy]

Thanks Higgy. What is the "canister" the tank is supposed to vent to? My vent just hangs down behind the motor

Cheers, CB

[higgy]

It is a charcoal canister used to remove volatile HC from the overflow air. I found one for mine cheap as it had been removed from my 906. Any canister from any bike will do. I think mine came from a 996 and I just zip tied it to the frame on the left side under the cover and ran the hose to it and from it. No more gas smell in the garage

[v2barn]

CB, my 906 is a UK spec bike and the vent pipe from the tank just vents to atmosphere as yours does behind the motor, nothing is missing from your bike, fit a cannister if you like? I know some American states (California) are very strict on emmisions and fit cannisters and a myriad of associated pipes, my garage smells like a petrol station anyway so i shall not bother, smells rather nice!
Good luck with your pipes, i must confess when i refitted my tank the sticker shown above above did confuse me for a while - 'Waste Fuel'??? 'Cannister'??? 'Fuel Return' and 'Vent pipe' would have been more of a clue!!!
Keep us posted on progress. Cheers Jon

[ducinthebay]

Is that jet in the return line needed? It seems that much of the problem with the Weber was too much pressure. Removing the jet would give you a lower pressure, but with plenty of flow. There will be some pressure from the resistance of the lines, and that would seem to be enough for the carb. No?

At least it works that way with the Dells.

Cheers,

[higgy]

Is that jet in the return line needed?

No, read our Weber doc fix that weber

i must confess when i refitted my tank the sticker shown above above did confuse me for a while - 'Waste Fuel'??? 'Cannister'??? 'Fuel Return' and 'Vent pipe' would have been more of a clue!!!

way to many gas fumes bet you blow your clutch out with air as well,Don't you