Weber progressive question

You mean the idle volume screw, right? And turned it out 3 turns, not in. That's rich. Should end-up around 1.5 to 2 turns out.

It came with 60 primary idle jet, probably. Go up to 65, then next to a

70, etc..

I never had a problem getting a good static idle on my DFEV. Where I did have the problem was the just off idle range until the main jet took over. The "letting the clutch out" range is awful. But it isn't the carb. It's my distributor.

Just for the fun of it, try swapping to the idle jet from the secondary, which should be a 50. This will make your primary side more lean. Just see how much worse it is. It should be worse. It's always good to verify. If that "empty hole" with your idle is now a whole lot larger, going up to 65 would be the correct direction to go. If that "empty hole" with your idle hasn't changed, something else is wrong.

What's your fuel pressure? It should be 2.5 to 3 psi, no more.

Also, try adjusting the closure point of the secondary. For me, too far was the throttle plate sticking to the venturi, but short of that was perfect. If I had it open anymore, the idle was rough and too fast.

That's not a bad settings. Your primary idle jet might be one size too small.

Oh, it really is your speed screw. Hmm... secondary plate open too far on its stop?

Mechanical pumps vary in pressure. Webers are very sensitive to fuel pressure. You can't give it greater than 3 psi.

The secondary idle jet doesn't do much of anything. The just barely open portion of it, so the primary is doing all the work on its main jet.

David, thanks for the response.

I have the idle mix screw out about 2 1/2 turns, which is the baseline setting. This seems to give the best fatest idle.

Actually it came with a 75 primary idle jet and a 60 secondary idle jet. I have tried 80 and 85 primary idle jets, which force me to turn the mix screw further in My problem is the idle speed scre -- the stop screw for the linkage. The baseline setting for the speed screw is no more than 1

1/2 to 2 turns in once the screw comes into contact with the linkage. The spped screw setting range I have to use (around three turns) is not affected by the larger primary idle screw I have tried.

The primary and secondary idle jets are physically different sizes -- the secondary is smaller than the idle.

I haven't tested it yet, but its a mechanical fuel pump so less than 5psi probably.

How does the seconday idle jet work. That is, at what point in the throttle/rpm range is it functional? Does it affect curb idle speed/mix?

Thanks again.

Right. And I suspect this is allowing gas to run out of the carb over night

-- would it explain the hard starting after sitting a couple of days.

I can see where this cause problems, but could this cause the low idle I'm having?

Since the link I posted above does not really link to the article, I'm going to post a section from it. This is what got me to thinking about the secondary idle jet. btw, to see the whole article, click on the link, go to bottom left of the page, click on engine, and click on weber tuning guide. Thanks again David.

Fron the article: Once you are happy with your primary jetting, you may choose to work on the idle jetting. This is a different technique and doesn't require removing the top of the carburetor, but it doesn't work well until the primary is pretty close. The technique is to drop the idle to a minimum value with the two adjusters (the mixture screw will be about two turns and the throttle screw at the minimum setting) as close to completely shut as possible while still keeping the motor running. You want maybe 750 rpm here. Now, slowly screw in the throttle adjust to speed up the motor to about 1500 rpm and listen to the progression. You want a smooth progression with no surging. A lean mixture may cause stalling. Now return to the low rpm and open the mixture screw 1/2 turn and do the test again. If it improves, then raise the idle jet to a 70 or the next size. If it deteriorates, drop one jet. Retest. The carburetor will run on the idle circuit, but since this is the smallest jet, it is the most likely to become plugged. If you lose your idle, check this jet first as it's the most likely to be plugged and the easiest to get to. If you just can't get the engine to idle without propping open the throttle with the idle speed screw, the secondary idle needs adjustment (if your carburetor has in idle hole below the secondary throttle plate). The secondary idle circuit has no metering screw so you will need to clean or replace the jet if adjustment is needed.

your idle jets (both) are WAY WAY WAY too rich. What size venturis?

john Aircooled.Net Inc.

Check your fuel pressure. It must be too high. That shouldn't be happening.

Thanks for the reply, John. Primary idle is 75 and secondary is 60. I ordered this kit from carbs.net and is was supposed to be for a jeep with a

258.

most guys selling the carbs have no $)*#&)&B clue how to tune them. They are almost always provided with the wrong jetting. They usually supply them with RICH jetting, because most folks will be able to get it running, and would never know the difference. It's really stupid that I have to help so many Jeep folks with their progressives, but it seems like nobody into jeeps seems to have a clue (at least if they are, they aren't sharing the info).

you'll have to buy about $40 worth of jets, and then spend a couple hours playing with it to get it right.

But before you waste a bunch of time, check your fuel pressure and float levels. The fuel pressure MUST be 3-3.5psi. The float level is wr>

From the clues it sounds like his fuel pressure is over 3 psi. Which, yes, he's running rich because of it. Yes, his jet sizes are big for a beetle. Venturis are 32/36 for the DGEV progressive.

Before he goes nutts with jet changes, I think he needs a fuel pressure regulator:

No need for the fancy one with the return line. Remember, 3 psi MAX for webers.

?keyword2=FSK0005

John, any advice on a starting point for jetting? Thanks for the help, and I'll share this info with fellow Jeepers, I promise :)

By the way, do you sell the jets? I'll gladly by them from you.

I have to check, but I thought the 32/36 is the THROTTLE PLATE size, not the venturi size. Example: a 40 IDF has a 40mm throttle plate, but has 28mm venturis when new, and a 44 IDF has a 44mm throttle plate and 36mm venturi.

John Aircooled.Net >

Thanks for the correction. I'll just shut-up and listen. I seem to do that best ;)

John, one question I have on 44IDFs. There's no vacuum send for the distributor. Not manifold vacuum, but the other one (venturi vacuum?). Anyway to add it?

And the choke assembly is missing with a block-off plate in its place.

I haven't run the engine yet and don't expect to really need a choke, but are there any other options from the cable/manual choke?

did you get this from us?

Our IDFs have the vacuum port in them. Duals/single?

John Aircooled.Net Inc.

Oops, I didn't mean to imply that I got them from you. No, I didn't get them from you guys.

Dual 44IDFs on a T4 engine. I just ordered a mallory unilite from you guys and opted for the one without a vacuum bottle. I'm asking a day late or so since the order on sunday, but can I retro fit a pair of 44IDF for a vacuum send? And possibly swap mallory distributors..?

Ouch.. sorry..

if they are new (last 2 years) they SHOULD have the proper port on them already

John Aircooled.Net >

Brass screw at the end got me confused.. Silly me ;)