Weber questions

Eljaro · #1 (**permalink**) 03-26-2006, 10:13 AM

I am experiencing fuel boiling problems after shutting off the engine.
Fuel boils inside the bowl and pushes out of the shooter right into the carb throat.
I do not think that any sort of phenolic carb spacers will be of any help, since the spacers I have now are fairly thick and do isolate heat enough.
I believe that what I need is a fuel return line to the gas tank.
Can anybody tell me or show me pictures of where I have to drain the excess fuel from to return it to the gas tank or back into the fue line?

Another new event with the webers is the exhaust popping with acompanying flames out the exhaust, which looks and sounds cool but gets tyring after a while. Is there anything to properly seal the individual heades pipes slipping into the exhaust?

Full Throttle Al · #2 (**permalink**) 03-26-2006, 10:20 AM

Do you have a fuel pressure regulator set to 3 psi? Sounds like a mechanical problem if not fuel pressue, ie, float level, bad float, bad needle and seat.

Brent Mills · #3 (**permalink**) 03-26-2006, 12:15 PM

I'm not going to speak with any sort of super confidence, but I believe the return line is just and extension of the end of the fuel line...Instead of stopping at the end carb, it goes all the way back to your tank.

With regards to the fuel in the bowls, I remember someone saying that just before your ready to stop somewhere, flip off the fuel pump and run the bowls close to dry. I'm sure it'll take a little while to figure out when the optimal time to turn off the pump, but it should reduce the problem of fuel pushing into the cylinders...

Eljaro · #4 (**permalink**) 03-26-2006, 02:37 PM

regarding the fuel return line I was thinking rather of something that would slowly empty the fuel bowl, like hooked up to the bowl drain screw.

Since I have a mechanical pump with a regulator set to 2.5psi, there is no way of turning it off before stopping the engine.
There also is a buildup of pressure behind the regulator when the engine stops. I guess that the heat in the engine compartement heats up the fuel in the line (or maybe also the air) and the expansion causes the pressure surge.

It can also be that the float valve does not close well. Who sells the D&G valves?
Thanks

Rick Parker · #5 (**permalink**) 03-26-2006, 05:17 PM

The return line to the tank if needed has to have a restrictor in the line such as a carburetor jet. It's purposeis only to allow the release of pressure in the lines after shutdown but could also be used to adjust fuel pressure (different size holes in the jet opening) while running. If it was an open line there would not be any fuel pressure developed.

Eljaro · #6 (**permalink**) 03-27-2006, 05:22 PM

I think the problem is heat radiation from the standing engine which causes the fuel to start boiling inside the bowls and flooding the throats.When there is no airflow from the scoop the heat goes up towards the webers and cook them

Better needle valves could help I guess.
Where can I get D&G Valves for the 48 IDA's?

I do not see many fuel return lines anywhere so I come to the conclusion that it is either not necessary or too complicated to fullfill.

I am also considering fabricating small heat shields to fit under the fuel bowl of the 48 IDA's.

Any suggestion regarding this flooding problem?