• From: Long Island, New York
  • Registered: 2005-08-25
  • Posts: 211

Topic: Leaking fuel from carburetor.

I replaced the gasket that goes between my carburetor and intake manifold. The engine is a 1500cc and the carburetor is a single barrel Solex. The problem that I am having is that gas is seeping out from this gasket. I checked the base of the carburetor and the intake manifold to make sure that they were not damaged or warped. They are perfectly straight. I made sure that both surfaces were clean before installing the carburetor. I made sure that the two 13mm nuts were tight (but not over tightened) but the problem still exists.
My question is did anyone have a similar problem and what did they do to fix it? Also, is there any type of sealant that I could use on the gasket to prevent this leak? I know that silicon product dissolve when in contact with gasoline. Is there something else out there that will work? Thanks.

Patrick

Owner of a 1970 Beetle.  Minus all the rust and most of my money.
  • From: Minneapolis, Minnesota
  • Registered: 2005-10-15
  • Posts: 288

Re: Leaking fuel from carburetor.

I don't think it's very likely that the gasoline is leaking out of the intake manifold to carb gasket.

I think your problem is more likely that your carburetor is leaking from somewhere else.  It could even be a severely worn throttle shaft.  Wipe down and clean the outside of the carburetor.  Then pay extremely close attention to the gasoline and where it's comming from.

Scott Novak

  • From: Colorado Springs, CO
  • Registered: 2004-03-27
  • Posts: 3,622

Re: Leaking fuel from carburetor.

Patrick: Ditto on what Scott offered. But also consider that perhaps it's a bad float valve (discussed many times in other posts) and perhaps you are getting some wash down of gasoline from an overfilled bowl. Scott, could this could show up as a wet manifold gasket? We know that a bad float valve can cause a flooded engine at start up so could it also show as a leak at the gasket?

FWIW, I always apply a light coat of wheel bearing grease to both sides of the gasket before setting it in place. This seems to provide all the "seal" I've ever needed, to prevent air leaks or gas leaks.

Clancy

  • From: Long Island, New York
  • Registered: 2005-08-25
  • Posts: 211

Re: Leaking fuel from carburetor.

Thanks for the response Scott. The carburetor on my engine is brand new. I replaced it four months ago. When I took off the gasket between the carburetor and intake manifold today, the gasket is soaked through.
I have another question. My engine is all stock, just like it was when it left the factory. Between the carburetor and intake manifold I have a throttle positioner bracket. Should there be a gasket between this bracket and the intake manifold? I did put one there and that gasket is also seeping fuel. Original there was no gasket there. I just thought that there should be a gasket where ever there is a metal surface making contact with another metal surface. Thanks

Patrick

Owner of a 1970 Beetle.  Minus all the rust and most of my money.
  • From: Long Island, New York
  • Registered: 2005-08-25
  • Posts: 211

Re: Leaking fuel from carburetor.

Thanks for the response Clancy. The fuel is defiantly seeping out of both gaskets. There is so much seepage that it is running down the frame of the intake manifold. I have ordered two new gaskets but I don't want to ruin them like I ruined the first two. As you probably figured out, I have the car off the road to prevent a engine fire.

Patrick

Owner of a 1970 Beetle.  Minus all the rust and most of my money.
  • From: Colorado Springs, CO
  • Registered: 2004-03-27
  • Posts: 3,622

Re: Leaking fuel from carburetor.

Patrick: Ok, check the float valve in the carb. Gasoline must be coming from the bowl or else you're set to run so rich, I can't believe that the engine will even run. A minor amout of liquid gas in the carb throat might be expected at certain operating conditions and maybe after shuting down a warm engine....but a steady "wash" will cause piston/rings/cylinder damage.

Clancy

  • From: Long Island, New York
  • Registered: 2005-08-25
  • Posts: 211

Re: Leaking fuel from carburetor.

Thanks Clancy.

Patrick

Owner of a 1970 Beetle.  Minus all the rust and most of my money.
  • From: Long Island, New York
  • Registered: 2005-08-25
  • Posts: 211

Re: Leaking fuel from carburetor.

The only thing the confuses me is that the engine runs great. It starts up perfectly and runs without any problems. I notice before I stopped using my Beetle that when the engine warmed up (like after a long ride) that the seepage had dried up. I feel that this is because of the heat of the engine had evaporated up this fuel. I will look at the float but I wish that I didn't have to.
I was wondering if the gaskets that I described before could be getting soaked during normal operation? Maybe the gasket is made out of a porous material. Like a cardboard. One of the gaskets was original to the engine and the other came with the new carburetor.
If you have a gasket handy, could you tell me if it is made of a special material. I know that you can not mix gaskets from a thermostat housing (on a water cooled engine) to a carburetor application. The gasket for the thermostat is not made to be in contact with fuel.

Patrick

Owner of a 1970 Beetle.  Minus all the rust and most of my money.
  • From: King of Prussia, PA
  • Registered: 2005-08-03
  • Posts: 420

Re: Leaking fuel from carburetor.

When the carb is functioning correctly, the gasoline that goes past those gaskets is already atomized.  Therefore, it is not possible for those gaskets to leak liquid fuel, unless there is another problem causing liquid fuel to be in that area.

Ted Wojton
70 VW Bus Westfalia,  2003 GMC Sierra
  • From: Minneapolis, Minnesota
  • Registered: 2005-10-15
  • Posts: 288

Re: Leaking fuel from carburetor.

I would concur with the others.  If your gasket is actually leaking the gasoline, there has to be something seriously wrong with the carburetor.

Some gaskets are made of better material than others, but even so, unless there is liquid gasoline runnging over the gasket, it's just not going to leak.  Also keep in mind that while the engine is running, there is a vacuum inside that manifold that would be constantly trying to suck air INSIDE the intake manifold, not blow the gasoline outside.

You'll have to watch the carb very carefully when the engine is cold, and when it's warm, when you're on a long trip,  or short trip, etc., for the clues that will help you locate the leak.

Scott Novak

  • From: Colorado Springs, CO
  • Registered: 2004-03-27
  • Posts: 3,622

Re: Leaking fuel from carburetor.

Patrick: One other idea....while you're about to remove the top half of the carb to check the float valve, check to see if the five(?) screws holding the top half to the bottom half are snug. Then when you remove the top half, check the gasket between the two halves to see if it might have a tear or flaw in it. If this gasket is faulty or not the correct one for the carb (there are various that would "fit") that may be the source of some leakage, but that would be on the outside of the carb....not sure it it would be enough to soak the manifold gasket. A long drive might also cause the carb to expand from the heat, sort of sealing the leak. Check the carb half mounting screws.

Clancy

  • From: Long Island, New York
  • Registered: 2005-08-25
  • Posts: 211

Re: Leaking fuel from carburetor.

Thanks for the responses guys. I'll remove the carburetor and check it out.

Patrick

Owner of a 1970 Beetle.  Minus all the rust and most of my money.
  • From: Northern Illinois
  • Registered: 2004-03-27
  • Posts: 1,105

Re: Leaking fuel from carburetor.

Don't think that just because the carb is new everything is A.OK. Especially if it is a Brosal made in Mexico. I've seen throttle shafts bad right out of the box on these.  What happens is when you shut the car off the engine temp climbs a little. The fuel in the carb expands and you get a few drips down the throat. Add to this a throttle shaft that doesn't seal well and a junky brosal needle valve and you have a recipe for a mess on your hands. I've seen them bad enough to start a small siphon and fill the engine with gasoline. A good friend of mine in Texas who didn't heed my warning just cost herself a freshly rebuilt engine as there was 1.5 quarts of gas in her oil and she ruined her bearings on an 80 mile trip.

Don't take this lightly.

These is a problem with your carb !  I have used both the junk cardboard gaskets as well as the good quality ( Armstrong flooring material ) gaskets and never had a problem. Yes there should be a gasket on both sides of the throttle adapter but if your no longer works ( do any of them ????) just remove it and cap the vacuum lines.

-Darby
  • From: Northern Illinois
  • Registered: 2004-03-27
  • Posts: 1,105

Re: Leaking fuel from carburetor.

Oh and I like Clancy's wheel bearing grease use too. (making mental note) I've used wheel bearing grease on non hydraulic valve cover gaskets for years to seal and make removal easier. (hydraulics I RTV seal in place)

-Darby
  • From: Long Island, New York
  • Registered: 2005-08-25
  • Posts: 211

Re: Leaking fuel from carburetor.

Thanks Darby and Clancy. My new carburetor is a Brosal. This is the carburetor that I wrote about (about two months ago). I purchased it from cpi1 in California. It has been a nightmare since I purchased it. Tomorrow I am throwing it in the garbage. Now I know for sure that Brosal is crap. I'll put my original carburetor on until I find a better replacement.
What do you think about this website: http://www.thesamba.com/vw/classifieds/ … p?id=64882

My original carburetor works nice but I feel that a new bushing needs to be installed on the throttle shaft. Did anyone send there carburetor to this place or should I just buy a new one. If I buy a new Solex 30 PICT-3 who should I buy it from and is there a good replacement for this carburetor?

Darby, I am going to take your advice and change the oil in my engine. It is probably contaminated with fuel.

Patrick

Owner of a 1970 Beetle.  Minus all the rust and most of my money.