TheSamba.com :: View topic

Fri Jul 25, 2008 5:25 pm

So.. what did we learn? I've posted a few times seeking advise on a flooding problem with Dual 34 Solex carbs. I've mostly blamed
the fuel pump and heat from the engine. The heat is right. Pump
is fine. Re-cap: After a drive, you shut down and about 7 minutes later
the carbs start dripping fuel down the intakes. It's the heat causing this.
I added 3 gaskets under each carb and there was a big improvement.
The studs and nuts need a insulating washer (next). Thanks for everyone's help,
sorry about asking after a few beverages :o

Fri Jul 25, 2008 5:38 pm

I don't really get started without a few Pale Ales in me....

Fri Jul 25, 2008 6:34 pm

I have never seen a case of heat causing carbs to do this, unless the engine was getting too hot.

Fri Jul 25, 2008 7:17 pm

Mark, the engine has never been hot. You have to wait
for this to happen. They are cheap carbs but run very well.
You can disconnect the fuel line and it will still happen.
So not the pump or float valves. Whatever is in the carb
passages will boil out. But... gaskets help. After shut down
the bowl feels very warm, but after a few minutes hot then
the gas comes out with gurgling noise.... heat from the intakes
are heating up the gas. stupid gas

Fri Jul 25, 2008 7:24 pm

Where is the fuel coming from? Aren't the float bowls vented? Is it the pump squirters, or the progression ports, or somewhere else? Everything has or should have vents, air bushings to eliminate siphoning, etc. Are these CB Solex 34's or ICTs, or something else?

Fri Jul 25, 2008 8:07 pm

Gas will expand out of the accel pump nozzle.

Fri Jul 25, 2008 8:18 pm

What model are they?

Sounds like the pump housing gets pretty hot and that the check valve(s) are very good seals with no bypasses. Still seems to me that they'd have to get damn hot to expand enough fuel out to cause that. Do the carbs get hot enough at that point that you can't hold on to them?

Fri Jul 25, 2008 8:34 pm

It is the heat, that is related to intake length.. size.
Mine stink. I could have twice the intake length.
But this is a Ghia. There was a big improvement when
I added gaskets under my carbs. Less heat transfer.
Carbs Behave

Fri Jul 25, 2008 8:36 pm

Allrighty. Glad you found the problem.

Sat Jul 26, 2008 10:41 am

I've got some dud carbs. They gurgle and drip on a cold
engine this morning. I'm at a loss and hope the vendor
I bought these from does the right thing.

Update: Adjusted floats a second time and flooding has stopped.
Thanks all