8 replies to this topic

[spark1]

Just fired up my 1380,45 weber, 285 cam, 123 dizzy and i've got fuel dripping off of the bottom of the K+N air filter but only on left side, Cylinders 3and 4

someone give me a clue as to what could be the cause? 

[IainStallard]

What fuel pump have you got? If it's an electric one, do you have a fuel pressure regulator?

[Frisco]

The float chamber overflow is over the left barrel as you look at it. I'd say either the fuel pressure is too high, the  needle valve is stuck or the float is burst.

[Craig89]

Could be a bit of grit or dirt in the float valve causing it to not shut off the fuel when the float chamber is full therefore overflowing. I have experienced this before. removed the valve, blew with compressed air, reassembled and problem solved

[spark1]

Its an electric fuel pump and yes I have a regulator fitted, 1 bar.

checked the needle valve and float is sound.

its almost like stand off, but why on one barrel?

[IainStallard]

Weber carbs need a fuel pressure of 2.5psi I think so you're pumping way too much fuel in

[Frisco]

1bar is way too high. Needs to be 4psi max

[spark1]

cheers,
I have struggled with the same problem prior to this rebuild(gone from bp300 to bp285 cam)
will drop the fuel pressure tomorrow and let you know.


thanks to all

[Artful Dodger]

1 bar fuel pressure for a weber?! Poor ole thing!!