Weber - Fuel Fountain!!

Just had my motor rebuilt which is fitted with Webers. All was well until I looked in my rear view mirror (100 miles in) and saw I had a fire going! Flames were burning between the front left and right chokes. Having put them out, and without sustaining any damage I suposed the problem was down to a residual fuel spill remaining after the rebuild. No problems, then days later and with 400 miles now recorded I witnessed an eruption of fuel (minutes after the motor was turned off) from the o/s front unit. Mopped that up only to see a fountain of fuel erupt from the rear n/s unit a couple of minutes after starting. So having used three lives up without bursting into flames I think it's time to sort this thing out.
What's going on chaps??
Thanks in anticipation,
Keith

 

[chuck smith]

to high fuel pressure or no return line

 

[Jac Mac]

Sound's more like a non-vented fuel tank or fuel filter between pump & carbs with a pressure rise from heat soak given that it happens after shutdown, or is the pump not turning off with the ignition.

Jac Mac

 

[40 Bud]

Try turning the fuel pumps off, let the engine run a few seconds before shutting down the ignition.

 

Thanks chaps. I'm reckoning Jac has where the fix is and Bud the prevention (I hope) in the meantime. Running preseure shows at 3.5/4 bar which I beleive correct?
KK

 

[Jac Mac]

I hope thats 3.5 to 4 psi---- not bar!!! If it is bar you might need 4 new floats. + a lotto ticket.

Jac Mac

 

[Lucas van Altena]

Keith,
I had the same problem, too high fuelpressure.
It cost me my engine, because it lost it's oilfilm at the cilinderwalls.
2 cilinders had no compression.
Now the engine is being rebuild.
Let this be a warning for you, do some thing on your high fuelpressuer.
I have learned my expensive lesson.

Regards,

Lucas

 

[Frank Catt]

Keith, are you running IDF or IDA Webers ? , there is a significant difference. They need a lot of care in setting up, and we have developed modifications that have now prevented the type of problem you are having. Firstly be very carefull to control fuel pressure, and either run the engine for a few minutes to lower the residual pressure in the feed lines, or put in a solenoid valve to dump the pressure automatically when you turn off the ignition, this is safer option. Secondly do not overfuel the engine, as Luc says, it gets expensive ! Frank

 

Jac, that was indeed psi - the benefits of my 3rd glass of sancerre were obviously kicking in! And to think I never even drank before owning one of these motors.

 

Re: Weber - Fuel Fountain!! - Pumps??

Ok, I am being told (off-line) the best pump set up is using Holley units and regulators. Currently fitted are unbranded pumps thru Filter King's.
Is this the way to go?
KK