28 Pict keeps flooding!
spacecrow
01-02-2008, 01:43 PM
Hello all. I am the owner of a 1965 Type 1. I am unable to run the engine because the carburator keeps flooding when starting. Of course I am well aware this is a terrific fire hazzard. I removed the carb, took off the top lid and replaced the float valve and float valve seal. This did not solve the problem. I assume a sticky float valve is the usual source of this problem. I am beginning to wonder if something else is happening here. The fuel line to the carb on both sides of the fuel filter was dripping wet with gas. Could another valve be the problem or maybe the fuel filter or fuel pump?
Also I did not pump the accellerator, I was careful to not do that, rather I let the engine move the fuel up.
Thanks for any reply, I am stumped.
Also I did not pump the accellerator, I was careful to not do that, rather I let the engine move the fuel up.
Thanks for any reply, I am stumped.
denisond3
01-03-2008, 02:26 PM
I can think of two other things that could cause such flooding:
1. Some gasoline has seeped into the float, and it isnt floating up to close off the needle valve. Take the float out and shake it - if there is any fuel inside it will slosh a little. If you do this after having dried the outside of the float, you will see some wetness appear wherever the leak is.
2. There is a vent for the float bowl, to let air & vapor escape as the bowl fills with gasoline. This essential vent typically opens to the carb throat somewhere within the space covered by the air cleaner tubing. On the 1200 engines I think it was a diagonal brass tube. If this vent is stopped up - the air is trapped in the bowl, and wont let the liquid level bring the float up to shut the needle valve. The normal fuel pump pressure coming into the bowl is enough to pump fuel through the jets a lot faster than the engine can possibly use it - so the engine floods. (Normally its only the difference between atmospheric pressure and the lowered pressure in the venturi tubes that draws fuel into the intake manifold.)
Though its unlikely, the fuel pressure could be way too high. I think VW carbs get by with about 3 psi. I think 7 to 9 psi could cause flooding.
1. Some gasoline has seeped into the float, and it isnt floating up to close off the needle valve. Take the float out and shake it - if there is any fuel inside it will slosh a little. If you do this after having dried the outside of the float, you will see some wetness appear wherever the leak is.
2. There is a vent for the float bowl, to let air & vapor escape as the bowl fills with gasoline. This essential vent typically opens to the carb throat somewhere within the space covered by the air cleaner tubing. On the 1200 engines I think it was a diagonal brass tube. If this vent is stopped up - the air is trapped in the bowl, and wont let the liquid level bring the float up to shut the needle valve. The normal fuel pump pressure coming into the bowl is enough to pump fuel through the jets a lot faster than the engine can possibly use it - so the engine floods. (Normally its only the difference between atmospheric pressure and the lowered pressure in the venturi tubes that draws fuel into the intake manifold.)
Though its unlikely, the fuel pressure could be way too high. I think VW carbs get by with about 3 psi. I think 7 to 9 psi could cause flooding.
smithjohnson
01-09-2008, 09:40 PM
nice info..
kelwa1
01-15-2008, 04:16 PM
If you have a carburetor flooding, it's a good bet you have fuel in your oil too. Say the carburetor floods or leaks fuel when the engine isn't running. Where do you think the fuel is going? It wont evaporate fast enough to keep from running through the intake, into the cylinders, past the rings, and into your crankcase.
If your oil smells like fuel, do not start, run, or drive the car. Fuel will dilute the lubricating properties of the oil, and in short order, can kill your crankshaft bearings. this means you will need an engine rebuild.
Take the carburetor off, rebuild it to Bentley manual specs, and watch it when you install for the first time. Be a good time to check the float/float valve specs or fluid in the float at the same time. Check valve clearance, timing, point gap,,,, set the idle and off you go.
Stock fuel pressure should not exceed 3 psi.
If your oil smells like fuel, do not start, run, or drive the car. Fuel will dilute the lubricating properties of the oil, and in short order, can kill your crankshaft bearings. this means you will need an engine rebuild.
Take the carburetor off, rebuild it to Bentley manual specs, and watch it when you install for the first time. Be a good time to check the float/float valve specs or fluid in the float at the same time. Check valve clearance, timing, point gap,,,, set the idle and off you go.
Stock fuel pressure should not exceed 3 psi.
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