PLEASE HELP with weber fuel leak

[zul8tr]

I just got a new set of 40 DCOE triple webers and am having problems with fuel leaking from the carbs. I bought a set years ago for another Z, and they worked great right out of the box, but I can't get these new ones to stop leaking.

These are the newer ones with the plastic floats. The documentation says that the closed position of the float should be 12.5 mm from the cover gasket and 25 mm max open. I have tried these settings and have even progressively moved the closed position all the way up to 20 mm, leaving only 5 mm movement of the floats, but they still leak.

I have read online that if you remove the jet inspection cover, take out the main jet that there should be 29 mm from the lower shelf to the top of the fuel level, + or - 0.05. I have 28.9 mm.

I got the Carter low pressure fuel pump that is not supposed to require a fpr, but since I had the leaking problem, I installed one anyways and have progressively lowered it to 2lbs, and still leaking!

I don't have a lot of fuel leakage, just a drop every minute or two from the bolts that hold on the air horns. Also, if I run my finger along the edge of the bottom carburetor cover, my finger will always come away wet with gas as well. While this is not a lot, I'm concerned about a potential fire with the gas droping on the header.

Oh... I have also taken apart and cleaned the needle valve that the floats push against to stop fuel from entering the reservoir.

I have corresponded with Redline and they tell me it has to be the float setting or debri in the needle valve, but I have adjusted the floats to 7 different positons and cleaned the needle valve each time for good measure.

Any suggestions, I'm really anxious to get my Z running?

[esmit208]

ZU

I had a similar problem with SKINNER UNION carburettors. If the float develops a leak meaning if fuel actually penetrates the plastic float it was not possible to stop the leaking issue. It was most evident when the engine was just turned off. Try replacing the floats themselves and then go back to the suggested settings.

Good Luck

2MUCHZ

[Marty Rogan]

I just got a new set of 40 DCOE triple webers and am having problems with fuel leaking from the carbs. I bought a set years ago for another Z, and they worked great right out of the box, but I can't get these new ones to stop leaking.

These are the newer ones with the plastic floats. The documentation says that the closed position of the float should be 12.5 mm from the cover gasket and 25 mm max open. I have tried these settings and have even progressively moved the closed position all the way up to 20 mm, leaving only 5 mm movement of the floats, but they still leak.

I have read online that if you remove the jet inspection cover, take out the main jet that there should be 29 mm from the lower shelf to the top of the fuel level, + or - 0.05. I have 28.9 mm.

I got the Carter low pressure fuel pump that is not supposed to require a fpr, but since I had the leaking problem, I installed one anyways and have progressively lowered it to 2lbs, and still leaking!

I don't have a lot of fuel leakage, just a drop every minute or two from the bolts that hold on the air horns. Also, if I run my finger along the edge of the bottom carburetor cover, my finger will always come away wet with gas as well. While this is not a lot, I'm concerned about a potential fire with the gas droping on the header.

Oh... I have also taken apart and cleaned the needle valve that the floats push against to stop fuel from entering the reservoir.

I have corresponded with Redline and they tell me it has to be the float setting or debri in the needle valve, but I have adjusted the floats to 7 different positons and cleaned the needle valve each time for good measure.

Any suggestions, I'm really anxious to get my Z running?

Sorry I don't have a resolution to your problem. But if I were you, I would build a splash shield under those carbs to keep gas well away from the carbs.

Leaky Webers burned up my first 240Z.

Good luck.

Marty

[Nigel1943]

I just got a new set of 40 DCOE triple webers and am having problems with fuel leaking from the carbs. I bought a set years ago for another Z, and they worked great right out of the box, but I can't get these new ones to stop leaking.

These are the newer ones with the plastic floats. The documentation says that the closed position of the float should be 12.5 mm from the cover gasket and 25 mm max open. I have tried these settings and have even progressively moved the closed position all the way up to 20 mm, leaving only 5 mm movement of the floats, but they still leak.

I have read online that if you remove the jet inspection cover, take out the main jet that there should be 29 mm from the lower shelf to the top of the fuel level, + or - 0.05. I have 28.9 mm.

I got the Carter low pressure fuel pump that is not supposed to require a fpr, but since I had the leaking problem, I installed one anyways and have progressively lowered it to 2lbs, and still leaking!

I don't have a lot of fuel leakage, just a drop every minute or two from the bolts that hold on the air horns. Also, if I run my finger along the edge of the bottom carburetor cover, my finger will always come away wet with gas as well. While this is not a lot, I'm concerned about a potential fire with the gas droping on the header.

Oh... I have also taken apart and cleaned the needle valve that the floats push against to stop fuel from entering the reservoir.

I have corresponded with Redline and they tell me it has to be the float setting or debri in the needle valve, but I have adjusted the floats to 7 different positons and cleaned the needle valve each time for good measure.

Any suggestions, I'm really anxious to get my Z running?

Not sure how you checked the closed position but if they are anything like Dellortos the closed position is adjusted by holding the cover vertically and measuring and adjusting the float position to the required distance.

Does this problem happen on all three carbs?

[oldhemi]

Mine leaked like that out of the box MANY years ago. I solved the problem by putting on a fuel pressure regulator. I set it at 3 lbs for normal driving and sometimes to 2 for constant highway driving and had no problem over the years. IIRC, the 260Z's mechanical and electric pump seems to put out about 4.5 lbs of pressure and the 40DCOE's wanted less than 4 lbs. Caveat: I did not hook up the return line at the time, so I dont know if that would have solved the problem w/o using a regulator!