Weber Carburator rebuilding DCOE

[hondo402000]

Well since I have my wiring finished, its back to the carburators, I couldnt figure out why I have a miss at 3000 rpm so I figuerd maybe they need to be cleaned on the inside and also when I let up on the accelerator I was always pertrubed that the idle wouldnt come down unless I blipped the throttle, So off with the webers. I attached several pics, one showing the carb top open. one of the acc pump jet plunger and one looking down the throat of the carb., Seeing how the webers are 5 years old. DCOE do have a pre filter and there was trash in them( thats probably because it was before I cleaned my gas tank) I did find some trash in the bowls and a little water. So cleaned them all out. The one thing that I could never figure out was why the butterflys would hang up. Well now I know why. the accelerator pump jet has a small brass plunger that is actuated by the throttle shaft and the plunger likes to get hung up on its return to normal position. So I took them out and buffed them to a mirrow finish, but as always one shot across the shop but I found it and no damage I was lucky there. Next if you look at the one pic you notice that when the butterflys are closed there is Light, I dont think god said when butterfly is Closed LET THERE BE LIGHT, just shows you how cheap things are made. they all have some issue but I guess thats why they have Idle screws and why some are open more than others.

 

[hondo402000]

the brass plunger

 

[hondo402000]

carb throat and how the butterfly not a good fit

 

[hondo402000]

well tomorrow they will go back on and see how they run
Happy thanks giving to all

Hondo

 

[poolboy]

carb throat and how the butterfly not a good fit

That's not the way it's supposed to look when the engine is at idle ?

 

[hondo402000]

sorry the carbs are off the car, and yes the butterflys should fit better but I didnt make them just have to deal with them

Hondo

 

[poolboy]

Hondo, that was a question, not a statement.
Seems to me that the throttle disc has to be slightly cracked open if the engine is expected to idle.
I was asking if that was the situation pictured. I realized that the carbs were not on the car but was the carb adjustment still set in the idle position ?

 

[hondo402000]

sorry! yep the idle screw was backed out all the way. On Webers DCOE carbs their is an idle circuit and it pulls air air and fuel thru the that circuit and bypasses the butterfly valves. I dont have my book in front of me its in the shop so I cannot be 100 percent sure but they should close better than that

Hondo

 

[DrEntropy]

With the idle set screws all the way out, the throttle blades should be sealed to the I.D. of the barrel.

Only the choke circuit bypasses the throttle blades, idle draws air from past the throttle blades.

With that blade misalignment, look at the SHAFT carefully to insure it hasn't been twisted from someone overtorqueing the shaft retaining nut(s).

The choke "barrel" seats can be crudded up and allow air past them, too. That can cause odd issues.

 

[hondo402000]

well since I purchased them new from pierce manifold, shaft retainer nuts on the sides have never been touched, So not sure what my options are for fixing them, and its next to impossible to get the screws out to remove the butterflies

Hondo

 

[DNK]

Have you contacted Pierce?

 

[hondo402000]

I thought about calling them today but then I bought them 5 years ago so most likely they wont do anything about it now. I did find out one thing, I checked the float heights, ALL WRONG the book says 15 mm which is .590 inch just one more issue thats made it difficult to tune them, So in closing, even when you purchase brand carburators off the shelf, you best check everything to make sure its set right!

here are the measurements I took this morning

one .557 inch = 14.7 mm
one .503 inch = 12.7 mm
one .450 inch = 11.3 mm

Hondo

 

[DNK]

5 years, ouch.
Know your pain. Remember the exhaust I bought from Moss 11 years ago.
They replaced the problem 11 years later.
You can ask,I guess.At least if you need parts they might help you out

 

[hondo402000]

I talked to the tech guy at pierce, he said a little light is ok, but he also told me the float setting should be 12.5 MM for the plastic foat, 15mm for brass they were still off, So back to the shop, and reset again.

UUUUUGGGG

Hondo

 

[hondo402000]

Well done and its running much better, now my spedo isnt working, must have pulled the cable out at the tranny when I took the spedo out, because the cable does not turn while driving just another thing to fix

Hondo