So I rebuilt and installed a 32/36 DFEV. I got it for a great deal. I installed it onto my 82 Brat. It runs and idles perfectly, but when I turn it off the jets are leaking into the motor. What is causing this? It floods the engine and makes it very hard to start. Thanks for any help!

If the Weber uses a float, sounds like the float s too low. 

How do I go about adjusting it? I didn't notice any type of adjustment screw? Thanks

That condition is most often caused by a leaky power valve.

You bend the tab attached to the float. Goggle "weber float adjustment". 

Check your float. I just eyeballed mine and it seems to work....

Take the top off, and turn it upside down. Adjust the tab so that the float is parallel with the gasket surface of the top.

Do not! Bend the tab by just pushing on the float with it resting against the inlet needle. It'll damage the tip and/or the seat.

Edited February 10, 201511 yr by spazomatic

OK. I'll take it apart this weekend. When I rebuilt it I didn't change the power valve, so maybe that's it. I think the float is gtg, but will still check. I noticed it doesn't do it all the time, just occasionally.

Thanks for the suggestions BTW!

Edited February 10, 201511 yr by iluvdrt

OK. I'll take it apart this weekend. When I rebuilt it I didn't change the power valve, so maybe that's it. I think the float is gtg, but will still check. I noticed it doesn't do it all the time, just occasionally.

If it doesn't happen all the time, you might want to make sure the power valve plunger/acuator is backing-off the power valve sufficiently to allow it to close.

 

Did you replace the power valve diaphragm when you rebuilt the carb?

I did not. Only the diaphragm on the accelerator pump. I couldn’t find a complete kit, so I just ordered the one from weber direct plus a new filter. It did come with a new needle seat, but nothing I found came with the power valve. Ill just order one. Im 99% sure the floats are good. It measured out on my ruler before I installed it.
 

I never even took off the power valve. Just cleaned everything with kerosene

 

I changed the power plunger diaphragm and it still drips when I shut it off. It leaks about 1/2 the bowl in then stops. The float sits level and only moves 2-3 mm while pressing the bearing.

 

I wish I knew what all of these things do. Could the thing the power plunger pushes down on be leaky? It seems fuel flows from the bottom of the bowl,up through the jets and then out the jet nozzles.

 

What does that button thing do at the bottom of the bowl?

Although, its not nearly as bad now.

Does the power plunger suck up until it looses vacuum from an opened throttle and then go down to press the power valve allowing more fuel in when at WOT?

I changed the power plunger diaphragm and it still drips when I shut it off. It leaks about 1/2 the bowl in then stops. The float sits level and only moves 2-3 mm while pressing the bearing.

 

I wish I knew what all of these things do. Could the thing the power plunger pushes down on be leaky? It seems fuel flows from the bottom of the bowl,up through the jets and then out the jet nozzles.

 

What does that button thing do at the bottom of the bowl?

The button thing at the bottom of the bowl is the power valve.

 

The plunger just pushes down on the power valve to open it, so if the plunger does not back off the power valve enough then it will hold it partially open.

 

The plunger is actuated by the power valve diaphragm that is located on the top of the plunger in the choke body of the carb.

 

Fuel flows in from the top of the bowl through the float valve and out the bottom.

OK cool. Maybe the valve itself is bad. I don't see how I can adjust either the vlavle or the plunger. Its not as bad as it was. Thanks for all of the help.

 

Next is jet issues. Under light throttle, right around 2800 rpms it falls on its face until the secondaries open. I need to see what jets I have because the carb came from Denver and I'm in social. I'm thinking they may be smaller. Its not a big deal, but I am super OCD with how my cars run. It also has a stumble specifically in 3-4 gear at about the same throttle position. No vacuums leaks. Every gaskets was replaced (even intake manifold), every hole and bolt chased with a tap and die, and every surface checked with a machinist's ruler.

 

The only thing I haven't done is do a compression test. I didn't think k I needed too because it ran fine with the hiatachi.

 

I am super impressed with the weber though. When floored, man does it scream. I may port the intake a bit to match the adapter plate. There is a noticible lip under the primary because the adapter plate is larger, and I can't help but think some of my drivability issues could be related to shitty air flow.

Sounds like its running lean. Presuming it was tuned correctly for denver altitude...its definitely got too small of jets. Find out the sizes you have in it now, and then buy yourself an assortment of sizes so you can dial it in to your OCD heart's content.

Im the same way...tinker till its juuust right. Makes for a fine running machine, but it can also be a time consuming PIA

Well do thanks for the help!

Does anyone know if the DGEV jets are the same as the DFEV? I am guessing they are, but as I found out in my 2 different rebuild kits, not everything is the same.

only experience I have with a weber is not good - bought used, never used it, onsold to a guy needing a weber, jinxed himself there and then - did not pay fully, it gave him same problem as his first weber, so there was something wrong with mine of course, he and his car building mates too tight or stupid to put a kit through it - he failed to pay the balance owing and avoided me ever since.....

 

I do know that the weber has a float and would suggest something different - fuel delivery pressure causing the fuel to leak out the jets. Would it hurt to crimp off the rubber fuel in line closest to carby to see if leak stops? If float chamber filling up and flooding, has to leak out jets sure;ly ?It may need a return line teed into fuel in and back to filter like EA81 from 1984 at least ?

Installing a return line would be hard since there is no outlet, I can check the fuel pressure though and perhaps get a regulator with a return. I have read Webers are happy around 3-4 PSI. I am running the stock pump (AFAIK), so maybe this is something to look into. Thanks for the tip

Its actually running very well. I ordered a jet kit today, and plan on porting the intake where the adapter goes to smooth out the lip thats there. I can't imagine that is good for air flow.

The return line fitting for a stock carb will work on the weber. Mine was much happier once i added that and a regulator. That wont solve the problem of it draining though.

My weber does not have return line hole like my hiatachi did. Do I just install the return line into the fuel supply hose and place the pressure regulator inline on the return line?

If you look at the old hitachi....there is a fitting where the fuel line flows in.

 

It is a "T" of sorts, with the main fuel line being 5/16" or so, and the smaller "T" of the side is a return loop to the tank...is like 1/8".

 

This is common for older carbed cars.

OK, I know what it is now, Thanks. If I am installing a pressure regulator, should it go into the return line to prevent too much fuel from getting recirculated?

Edited February 19, 201511 yr by iluvdrt