double Y was for the tanks w/o return connection

the 906

OK, so quite a bit different from my setup. First, my petcock had no filter attached. Second, I have three orifices into the gas tank, besides the filler: the supply, the vent, and the return (California tank I imagine). Vent and return are on the back of the tank. Cali owner's manual says the return goes to the rear tube; vent is the one about 2" in front of the return. Not sure if the length of return gas line combined with that tube's rise to the top of the tank (before dumping its gas) may be compensatory for the volume reduction that the 'jet' may provide in the euro model? I've blown thru both tubes, and they are clear.

The tank is clean metal inside, with only a small amount of rust; as I said, there was a small 'pile' of it on top of the petcock when I had the tank apart to inspect and reseal the sending unit. Petcock filter nonexistent. As per FAQ's substituted NAPA fuel filter for the original clear canister. Flow seemed fine thru the return tube into the baster.

More to follow this weekend after I hope to receive my rebuild kit and jets. JayH did not yet respond, but with an oval air filter replacing the airbox, is a more free flowing exhaust mandatory?

As always, thanks much.

The one shown in the manual is the first solution, the one you have is the second used for all 750 and 906. Very easier to manage fuel flux and avoid vapour lock.

Ciao Nicola,

Since I will use a Mikuni mechanical fuel pump, would you recommend me to use this flow back system or just a single hose from fuel tap to pump and again a single hose from pump to Weber?

Frank

Ho spesso visitato Siena, è una bella città (mia moglie è Italiana)

Thank you all for your assistance with information, and in sorting out my carb problems.

Synopsis after rebuild and substitution of jets per jayh, et.al:
Needle Jet: 175 (came with rebuild kit; 300 was the original)
Idle Jets: +/-53's (reamed out 50's that I bought)
Main Jets: 165
Air Correctors: 185
Float Bowl set to 43mm/51mm
Accelerator pump cam profile changed to a more mild version of jayh's concave smooth curve.
K&N-style oval air filter with pipe outlet to which I connected breather hose, and original us-spec exhaust.

Center stand results: bad stumble (sounds like a sneeze) at idle and at acceleration from idle.
Tried lowering float to 46: no change.
Put original (cleaned) 300 Needle Jet back (with new needle (needle profile the same)) and set float back to 43/51mm.

Center stand results: Great idle; backfire right at initiation of acceleration.

Went for a 15 mile ride...2000-4000 rpm, bad sneezing stumble; above 4000 rpm - an absolute joy. Fantastic acceleration up to 9000 rpm.

First try at fix: re-installed original 55 idle jets. Center stand test: Sounds absolutely perfect! Nice idle, and no apparent hesitation on acceleration!

So.....now...........why are my clutch hydraulics failing??? Ah the goddess bites again. No ride. Tore the clutch cover off, and no apparent leaking of oil. I had taken the clutch apart to replace the clutch side cover gasket, so all was cleaned, inspected, and ok. Assume hydraulic issue - will get rebuild kit for master cylinder and new o-ring (which were both suspicious original components).

Today's quote: "Is that my turkey baster? (wife)" "No, it's our turkey baster. (me)" "That's ok, I'll buy a new one. (wife)"

Thanks again!

G:

BTW, I did insert a small(er) diameter brass tube in the return fuel line to reduce the volume to the tank. And, from another petcock I had laying around, I did find a fuel filter that matched your photo...so that is now installed as well.

Thanks again.