Fuel still disappears from carb.

[Peer81]

Hello everybody.

I have a small problem. I rebuild my E4ME carb, tapped and installed the bottom plugs under the primairie and secondairy jets, with the right epoxy. Put the carb (w/o the airhorn) on a "stand" on the bench and filled the carb with fuel and a white piece of paper under the carb. First day about 1/2 of the fuel is gone and no fuel has dripped on the paper, second day another 1/4 was gone. I was thinking well fuel evaporates so I put a piece of plastic on top of the carb (w/o the airhorn) and tried again... same result but no fuel under the carb and the plugs were feeling dry!
So I reinstalled the carb on the engine. It runs great but when I leaf it for 2 days I feel there is no fuel in the fuel bowl.

So my idea is, the fuel could be leaking from the original plugs under the acc. pump and the one on the other side (horizontal). I have a return stop inside the fuelfilter so no fuel can return down the fuel lines so that isn't the problem. Anybody else has an idea on what the problem could be?

Greetings Peter

[Peer81]

I was hoping somebody would have an idea where I could look from some weak spots?
I read somewhere that some E4ME fuel bowls are not the best casting and they could leak fuel from different spots is this true?

Second. I was hoping somebody could tell me how many days fuel should remain in the fuel bowl before it evaporates?

Greetings Peter

[Cliff Ruggles]

The only effective way to find leaks at bottom plugs is with compressed air and soap/water.  It will find the smallest leaks past the plugs.

Evaporation can occur quickly, depending on underhood temperatures and how much heat is soaked up by the carburetor after turning off a hot engine.

I've bench tested the new fuel, and it's still around after a week, although it's getting pretty low in the bowl.

Seems to last a lot longer in colder months.....Cliff

[Peer81]

Small update on the problem.
Had the time to pull the carb apart and see what the problem is.
First the gasket between the fuelbowl and the bottom part is a little wet and darker colored around the opening where the primaries are hanging in. Same thing for the primaries themselfs. The epoxy is darked colored then the same epoxy on the secondaries.
So I would say, something in the first opening (in the gasket) is leaking fuel. Problem is, I removed the original plugs, tapped the holes and put in the new plugs with epoxy in the treads of the plugs and the in the hole treads. I tested the primarie tubes with soapy water and compressed air, no bubbles, even with the primaries hanging with the bottom in some water. With compressed air I see no bubbles in the water and even no wrinkles in the water from some air.
In the same area there is a third plug from the tube that is sticking out of the bottom with an angle. I have no idea where its from or what its for (sorry cliff's book is not around right now) and I couldn't find a way to test it right with soapy water and compressed air.
If somebody had an idea please shoot.

btw. on my other fuelbowl, I replaced all the plugs. But the plugs from the acc. pump and the angled plug looked a little bigger then the ones from the primaries. So on this one I reader not change them before I know for sure if they are the same size.

Greetings Peter

[Peer81]

I had some time to go through Cliff's and Ro's book but in both there is no mention where the angles plug (in front of the primarie plugs is for. So if somebody knows?

Of course I can just put epoxy on the plug and see if the problem is gone but I think its better to get the the problem in a rational way and not guess work.

Greetings Peter

[sweathogg]

did you degrease ( w/ acetone or brake cleaner )  the new threads and plugs prior to applying the expxy ?

sweathog.

[Cliff Ruggles]

The cross drilled hole is for the accl pump passage.  They seldom leak, and you must take care if threading and installing a plug in that location, not to go too deep.....Cliff

[Peer81]

Thanks for the heads up Cliff.

On my other fuel bowl I replaced all the plugs so I know the plug can only be about 3 "threads" deep. I think this time I'll first epoxy it without installing a new plug. I think it's a little to tricky to thread and screw in a plug if I don't need to.

When I have uploaded the pictures I'll post them here.

Greetings Peter