Webber carb jetting question

[Guest Anonymous]

I have a 1976 2002 with piano top pistons, a 285 camshaft, a Webber 38/38, a E12 head, and even 155 lbs. compression. My question is thus. What 4 items should I buy jets, etc in order to improve my idle? Car has good smooth power but runs/idles rich with the common lumpy idle. Also is Redline the best vendor of Webber parts? If it matters I have a Tii exhaust manifold with stock exhaust system and a recent head gasket replacement. When I replaced the head gasket a year ago I found the piano top pistons that do not allow me to install my brand NEW factory head which is a E21-2.0 1976 49 state head.

[Napes]

Another good source for Weber (there is only one "b") carb jets and parts is piercemanifolds.com.

Many on this board use them, and they have been very helpful in all my transactions with them over the years.

Bob Napier

[TobyB]

I'd buy a new distributor.

A 288 should idle like a kitten.

t

[Guest Anonymous]

My car has a reman distributor. My question of what parts do I need for this carb to reduce the fuel flow and correct the idle speed. It is common knowledge that when one buys a NEW carb one has to replace about 4 parts (jets,etc) in order to match the carb to ones particular engine. I have seen posted in the past others who list 4 different parts with numbers identifying sizes of jets. I live at sea level. Can someone help me with identifying these 4 small parts?

[c.d.iesel]

...do you have one-of-the-six published books

on How to Weber which shows every tiny bit in yer carb,

with every weber part number, that you can then order from

Pierce Manifolds to lean out your idle ......?

you need to list all the jet sizes currently in your 38/38

idle_____

air correction_____

main_____

float level ______

and how you set your ignition timing which needs

to be done and then left alone BEFORE you start

to fiddle with your carb

[Guest Anonymous]

Does anyone have an engine setup similiar to mine that has successfully changed the four parts and ended up with a GOOD idling motor with their 38/38 Weber car????? If so what were the numbers of your parts please. Yes I have a low mileage reman distributor and electronic ignition-(points deleted). Yes my motor is timed correctly. If you cannot answer my part number question please do not reply. My carb is a Weber 38/38 DGAS. NOT a DGES!!!!!!

[fst2002]

Have you checked the jet size? Start there and confirm all main & idle jet sizes. WeberUSA has much info but no two engines are alike so what works in yours might not work for someone else.

Also read articles on this forum... good stuff! Always helps me.

[72koop]

040-.045-.050-.052-.055-.060-.065-.070

You need idle jets. .050 has been used. Buy them in pairs and buy two sizes to tune.

It is likely the carb has .060 as that idle is for a 3.0motor , stock out of the box.

Now, pls. take the sage advice of the others here.

The most important is how may turns out are your idle screws and are they the same ( balanced? ) If one is more out than the other you might have found your problem.

If rich they would not be open much, say one turn out. Two turns out is about right.

[jerry]

For reference, i've got a schrick 292 cam, 9.5 CR bathtub pistons, 121t head on a used engine, running with a 38/38 and manual choke.

My settings:

emulsion tube: F-50

air corrector: 180

accelerator pumpjet: 70

fuel valve: 250

main: 150

idle: 55

it was idling nice but on the rich side. my idle/air mixture screws were less than 3/4 turn out when adjusted by someone more knowledgeble than me (JP Cadoux, A1-Imports). In order to get more turns on the idle/air screw, I was told to install smaller idle jets.

i just installed 50's in the idle last night. i will have to tinker a little more but overall, the car seems okay for the most part.

i have not played with the Mains since the tuning has been at idle speeds. i have slight hesitation at idle now with the smaller idle jet installed, but don't know if that is a result of my own lack of adjustment ability or the resized jets. i do not seem to have any hesitation when going from idle circuit to the main circuit, very nice response at 2500RPM and up.

[Guest Anonymous]

Thank you Jerry. This is the kind of reference info I have been looking for.

[Simeon]

Does anyone have an engine setup similiar to mine that has successfully changed the four parts and ended up with a GOOD idling motor with their 38/38 Weber car????? If so what were the numbers of your parts please. Yes I have a low mileage reman distributor and electronic ignition-(points deleted). Yes my motor is timed correctly. If you cannot answer my part number question please do not reply. My carb is a Weber 38/38 DGAS. NOT a DGES!!!!!!

Whoa! Way to make friends and influence people. These folks are trying to do you a favour here.

[TobyB]

If you cannot answer my part number question please do not reply.

Now that's just not a good way to make friends and influence people.

But since your question can't be answered with part numbers, here's what

I've found out when trying to get the 38/38 to idle.

If, as you say, it's idling rich, just close both idle screws.

It should stall. Refuse to run at all. Just crank, as long as the choke's full open.

If it runs, then the throttle plates are open too far, and

you'll need to troubleshoot that.

If it passes this test, then back the idle screws out to where they were initially,

start it, and lean it out a bit. Try to keep the 2 balanced, as in, the same

number of turns on each.

The BOOKS say that there's a range of turns (something like 2) out that

tell you that your transition jets are right, but I didn't find that to be

true for the 38/38 on a 2002, because....

The 38/38 doesn't have idle jets, as such. It passes fuel through the

TRANSITION jets to the idle circuits, but those screws set the idle mixture.

Now, if it's leaned out and DOES idle well, there's a good chance it'll have

a hole between idle and 1500, or something similar. NOW it's time to

pull the jets that are in there, get the numbers off them, and go up a size

or 2.

Or down, sometimes. Depending on what's there...

No part numbers here.

t

but most of the idle problems I've had came back to idle timing.

Or balance between the idle screws on a 38...