leaking weber carb

My engine has 48 IDF Webers. The car is a 99 IM, but with less than 4,000 miles.

One of the Webers has just started leaking fuel. This occurs when the car is sitting (I guess when it's driving also, but I haven't driven it since I found the leak). I have snugged up any plates with gaskets that I can find (one of each side of the carb body), but it still leaks. Could it be a grommet on the accellerator shaft? They are a pain to get at to see where the leak is and to tighten any screws. Next option is to remove the carb. I'm not that familiar with Webers (S.U.s I know)

The fuel is leaking externally, and ends up on the base of the carb, on the side internal to the engine.

Thanks

Bob
(Message Edited 10/1/2003 5:35:30 AM)

Be concerned about engine fires, ask me about them. Your problem is probably an easy fix but tend to it before driving.

Weber IDF carb bodies have internal passages that are drilled from the outside and then plugged; it's possible that one of your carbs has a leaking plug. I would take the carbs off and find out for sure where the leak is coming from. If it's one of the plugs use a center punch at the middle of the plug and give it a rap with a small hammer to expand it into the carb body.

To check for leaks clean off the carb, remove the top, then fill it up with isopropyl alcohol that has some red food coloring in it and watch for any leaks. Also check the screw in top fittings/gaskets for leaks, and of course the fuel lines at the carbs.
(Message Edited 10/1/2003 7:09:29 AM)

As usual, George, thanks for your advice!

Webers are new to me, as are high performance VW engines and oil systems ;-)

Bob

And then there's my IM from Hell. Started to backfire...thought it was either an exhaust leak or a plugged idle jet. It was a plugged idle jet, but now it will only run on 3 cylinders. Talk about a love/hate relationship with a vehicle.
Ron

Ron,
As Thoreau said- "simplify, simplify". I had dual IDFs, they were great... in theory. In the real world, my 1776 with dual ICTs is pretty easy to keep running like a watch.

Sometimes I wonder if we're not asking more from these little air cooled four bangers than what they can reliably deliver? My 68 Ghia Cabriolet with one little Solex carb and 1500 c.c.s used to run all day (and will again, should I ever get around to restoring it).

But, it's not a speedster...

I know that some members on this forum have stated that they run dual Webers and have absolutely no problems. I'm not one of them. I've had a fair amount of problems with them...usually plugged idle jets. It seems that almost any tiny little piece of crud will plug them, and I'm running two fuel filters. On the other hand, I put 65 thousand miles on a pair of Kadrons, with the old, crappy linkage, and NEVER had any problems with them. Had them looked at every 3000 miles, but they never needed more than minor adjustments.
Ron

Here's the deal for running dual IF's without any clogged jet problems.

1. Check your gas tank - if it's full of rust and/or paint particles remove it, have it cleaned, and coat the inside with the POR 15 fuel tank sealer kit (or some other good sealer). If the tank was cruddy clean and flush fuel lines, fuel pump, and carburetors. Use only gasoline rated rubber fuel lines (others may shed particles from the inside of the hose).

2. Install a VW cannister style fuel filter in line at the bottom of the tank.

3. Make sure your air filters seal in their containment boxes and use K&N filter elements - the K&N "look-alike" and some other filters usually allow fairly large particles of dirt to pass through after a while.

You know George, it just takes the smalled piece of crap to clog the idel jet.
Ron

My carbs run great. It's just a tiny leak that I have not been able to find yet. Carbs only leak when the car is sitting (engine off). It's not from any of the gasketed plates on the sides of the carb.

I am going to try George's suggestion of adding coloured alcohol and see if it shows the leak. I guess Scotch would work?

Bob

Ron O. - yeah, I know, that's why you have to have both fuel and air filter integrity as stated above if you don't want to deal with clogged jets.

Right, Jake?

Took the carb off the engine, carefully checked everything, then took it to my mechanic friend. He and I disassembled it, checked everything, and found no problems. Float was fine, gaskets intact, everything super clean inside, no obvious signs of where a fuel leak was happening. We replaced one fibre o-ring with a brass one.

So, back it goes on the car and I'll see what happens.

There's still a leak somewhere. Just leaks down to the base when the car sits and after it cools down from a run. I'll have to do more checking, I guess.

Set the leak on fire and see where it leads to.
Ryder Lake Ron

My 2 cents. This is day two with my A.J. Set of Kadron

Dear Ryder Lake Ron:

I know exactly where the leak will lead to. You, after eating three bowls of chili...

Bob

David, thanks for the plug, but most of the ideas I post here are not original with me but learned from someone with more experience over the years. I've made very few original mechanical "discoveries"...

George: I just tried your idea - isopropyl alchohol with food dye in the carb, and found the leak. There is a very tiny crack in the carb body.

I am considering carefully opening up this crack just a little with a dremel tool from the outside of the carb, and then applying some type of metal compound to seal the crack.

Comments, anyone?

RJC

Robert,

That may work but I sure wouldn't tell your insurance company about either the leak or the fix.

A new set of Kadrons will run you $320.00 or so. It is worth the peace of mind. (((( FIRE ))))

JB Weld or aluminum epoxy will work as a seal - glad the alcohol and dye worked for you.

use the sealant, it'll work fine. stop by a fuel tank/radiator repair
shop and ask for a small amount of fuel tolerant [fuel tank coating]
sealer [i assume the crack is to the bowl, "leaks when shutdown"]
it'll work wonders. if you live near an airport [local] ask a
general aviation mechanic for "prc", used to seal [aluminum]integral fuel tanks. good luck

Yes, the crack is at the bottom of the float chamber.

Thanks for all the good advice, gentlemen.

Bob

David, Bob's motor is just too big for Kadrons.
Hey Bob, I just, for the hell of it, priced a set of PMO triple carbs for my 911 pickup (still having cold start problems). $3000 US!!
Ron

Ron:

If you spend $3,000 on carbs, you'll get more than a cold start from your wife!

I think I got the leak fixed - those little dremel like tools are certainly useful.

Bob
(Message Edited 10/9/2003 6:50:59 PM)

I should have known. But cant A.J. Take a stock set of Kadrons and trick them out to run on larger motors?

This is from A.Js Web site.

The 46mm IDK Power Kit.
So you are thinking of getting rid of your carbs because your building a bigger motor or the 40mm
kadrons you have now are just not enough. What if you could just upgrade your carbs that you have now.
How does 46mm sound ? The new LowBugget.com Power kit.
The kit includes:
(2) NEW BIG 46mm throttle bodies complete,
(2) new C&C venturies of any size to fit your motor combo, these are specially designed to work
with the 46 mm throttle bodies.
(2) Idle jets of any size, 50, 55, 60, 65. 70, 75, 80
(2) main jets of any size, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185,190
(1) Air Top kit that adds up to 7cfm,
(1) Vent Kit that will allow you to run as hard as you want without that stumble that has plagued the Kadrons.
All the gaskets to make it an easy swap from the stock 40 to a 46 IDK.
$199.99 with all the instructions.