mixture screw 5 1/2 turns out leanest best idle

[copacetickid]

Got a weber 32/34, and I've been fighting with it for too long.

 

I posted a while ago thinking there might be a vacuum leak because I couldn't get it to cruise without serious hesitation. I took it off, cleaned it from top to bottom and sanded the base flat (it was slightly warped). There's no chance of a vacuum leak now, but I'm having the same problems...

 

I readjusted the idle according to these instructions (for the millionth time), and when warm no choke, it won't even run rough. I have to back it out to 3 turns to get it to start and the sweet spot is at about 5 and a half turns out, where it's supposed to be no more than around 2. I know that's supposed to mean that you probably need a larger idle jet, but it just doesn't make sense...

 

The engine is a recently rebuilt L20b, and I've read in numerous places that a size 60 primary idle jet (which it is) should work great. This leads me to believe that something else is wrong, but I'm starting to go crazy trying to figure out what it is. The idle circuit passages aren't blocked, there's no vacuum leaks, the bowl is always full...

 

There's still a hesitation while cruising (< 1/2 throttle, tells me it's probably the idle circuit) that doesn't go away by tweaking the mixture rich or lean.

 

Also, the only other thing amiss is that the number two cylinder plug is always covered with black gunk, while the others aren't. It's was like that before the rebuild too, it's as if only number 2 is getting a rich mixture and the others are too lean. What could be causing this??? 2 AND 3 I might be able to understand... but just 2?

[ggzilla]

Vacuum leak. It is dry black (rich) or gooey black (oil burning)? Time to take a compression test. Maybe the cylinder itself is bad.

 

Warped carbs almost never work right even after filing/sanding. Think about how it might have gotten warped ... something was really wrong with it. Manufacturing defect?

[copacetickid]

Vacuum leak. It is dry black (rich) or gooey black (oil burning)? Time to take a compression test. Maybe the cylinder itself is bad.

 

Warped carbs almost never work right even after filing/sanding. Think about how it might have gotten warped ... something was really wrong with it. Manufacturing defect?

 

More like cranking down too hard on it... it was only slightly warped near the corners on one side, don't see how it could affect the idle circuit on the other side of the carb.

 

It's gooey black on cylinder #2... but like I said I just rebuilt it, and it's always been like that. I've done at least 3 compression tests in the last month, all consistent 180 185 185 180, cold. I guess oil could be leaking in through a valve, but the head got a valve job with new intake valves and guides in #2 and #3.

[Jester]

So have you done any jet work yet. Try going up a couple sizes on the idle jet and see what that gets you. Should put you closer to the recommended 2-2 1/2 turns.

[banzai510(hainz)]

Borrow another Weber DGV!!!!!!!and swap it .

 

ask Zuum 510 and Datto 510!!!!! esp if this was a used DGV that was installed.

[racerx]

yeh, that's too much turning. go on line and chgeck out Pierce manifold in Gilroy ca., they could recommend proper size.

[motavated]

This is what I did. Warm up car then turn off. Turn both screws all the way to the right. Then the distributor I lined it up right in the - indicator. Adjust the Carb peddle line so it has be a little loose. Then turn on the car. Let it idle then adjust the gas to the left a little. The adjust the air... Play with it. Took me a month to adjust my stupid carb.

[hang_510]

This leads me to believe that something else is wrong, but I'm starting to go crazy trying to figure out what it is. The idle circuit passages aren't blocked..

are the jets clear also?

sounds like they may be partially clogged/gummed up.

[racerx]

Check out weber tuning guide under general technical. Hopefully this helps. You can adjust the carb while car is running.

[copacetickid]

So have you done any jet work yet. Try going up a couple sizes on the idle jet and see what that gets you. Should put you closer to the recommended 2-2 1/2 turns.

yeh, that's too much turning. go on line and chgeck out Pierce manifold in Gilroy ca., they could recommend proper size.

 

Yeah, that's the next step, but what really bothers me is that I shouldn't have to, which makes me think that something else is wrong. I should find out what size idle jet people use.

 

Everyone with a weber 32/34 on an L20b: what size primary idle jet do you use?

 

Borrow another Weber DGV!!!!!!!and swap it .

 

For serious. Does anyone have one in the south sound area they're willing to let me borrow?

 

This is what I did. Warm up car then turn off. Turn both screws all the way to the right. Then the distributor I lined it up right in the - indicator. Adjust the Carb peddle line so it has be a little loose. Then turn on the car. Let it idle then adjust the gas to the left a little. The adjust the air... Play with it. Took me a month to adjust my stupid carb.

 

Wha??

 

are the jets clear also?

sounds like they may be partially clogged/gummed up.

 

not a chance, I just soaked everything in carb cleaner and blew out the passages with compressed air. It's clean as a whistle.

[motavated]

Thats how I tuned my truck. Rides really good now.

[banzai510(hainz)]

I have ran 50-55-60 and not to much change.

 

the idle jet is the brass screw on the side B) in photo.

pull out and see if dirty

 

datto 510 and Zuum had a proplem with a carb on datto510 521 truck.

I said swap the carb. There was a weber on there already. They was going to swap a stock carb back on. I said best to swap anothe weber as you dont have to swap around the adapter shit gaskets ect.. Just bolt it on then youll know!!!!!!!!!

 

 

you wrote;

There's still a hesitation while cruising (< 1/2 throttle, tells me it's probably the idle circuit)

No are are already entering the main circut

 

If your ignition is good ???????????and wasnt messed with I would think its still the carb.

Edited January 26, 2009 by banzai510(hainz)

[datto510]

He is right. It runs like a champ now.

 

I have ran 50-55-60 and not to much change.

 

the idle jet is the brass screw on the side B) in photo.

pull out and see if dirty

 

datto 510 and Zuum had a proplem with a carb on datto510 521 truck.

I said swap the carb. There was a weber on there already. They was going to swap a stock carb back on. I said best to swap anothe weber as you dont have to swap around the adapter shit gaskets ect.. Just bolt it on then youll know!!!!!!!!!

[copacetickid]

the idle jet is the brass screw on the side B) in photo.

pull out and see if dirty

 

Trust me, I know where the jets are on this thing. I've broken it down to nothing, cleaned it, and put it back together more times than I can count. I should be in the fucking army right next to the guys taking apart their guns. The idle jet is clean.

 

I said best to swap anothe weber as you dont have to swap around the adapter shit gaskets ect.. Just bolt it on then youll know!!!!!!!!!

 

This is a freakin great idea, but I don't have another carb. I even gave my stock carb to taajd and I think he sold it on ebay.

 

you wrote;

There's still a hesitation while cruising (< 1/2 throttle, tells me it's probably the idle circuit)

No are are already entering the main circut

 

If your ignition is good ???????????and wasnt messed with I would think its still the carb.

 

I've read a number of times in weber manuals and on forums that the idle circuit has a huge effect on performance all the way up to 2/3 throttle. It could be the main circuit, but since the idle mixture screw is so much farther out than normal, I was just thinking it's probably the idle circuit

[banzai510(hainz)]

If you didnt live so far away I would loan you my New weber DGV

Im in Covington,Wa

 

I meet Joe(Zuum 510)

he had a proplem on his 510. Give it gas it would NOT rev up.

I swap a carb on there only to find out the distributor was off a tooth or timming plate

 

 

PS I hada plugged idle jet and it seemed I didnt have to go too much over idle to get in the main circut.

 

somebody should have a extra weber to loan you. It saves alot of time trouble shooting,Believe me.

Edited January 27, 2009 by banzai510(hainz)

[zed]

Are you getting good spark to plug no 2? Might explain the loaded plug?

[copacetickid]

Thanks hainz, I appreciate the offer. I guess I'll just look for a stock hitatchi. I'd get another weber, but they aren't nearly as cheap.

 

 

Are you getting good spark to plug no 2? Might explain the loaded plug?

 

I know I'm getting at least a decent spark in #2, how do I tell if it's "good"? I got a new rotor, cap, wires and plugs about 1300 miles ago, and I've double checked the gaps. There's certainly no misfires...

 

One time when I was doing a compression test, I cranked it without the plugs in and fuel squirted across the garage out of number 2 plug hole, but none of the others. I thought 'wtf...' but didn't remember until now. What the hell could cause more fuel to come out of only one cylinder!?

[yello620]

I am running a Weber 32/36 on a L20b with a 60 main idle jet also, and i am turned out about 3.5 turns at least. Yes, i need to try a larger jet. I just havent done it. The 32/34 and 32/36 should be the same on the idle circuit as the secondary should not be doing anything yet. I plan to try a 65 idle jet, but when i make an order i will probably order a 65 and 70 because shipping is almost as much as the jet itself. Might as well get two jets shipped on one bill.

[racerx]

Thanks hainz, I appreciate the offer. I guess I'll just look for a stock hitatchi. I'd get another weber, but they aren't nearly as cheap.

 

 

 

 

I know I'm getting at least a decent spark in #2, how do I tell if it's "good"? I got a new rotor, cap, wires and plugs about 1300 miles ago, and I've double checked the gaps. There's certainly no misfires...

 

One time when I was doing a compression test, I cranked it without the plugs in and fuel squirted across the garage out of number 2 plug hole, but none of the others. I thought 'wtf...' but didn't remember until now. What the hell could cause more fuel to come out of only one cylinder!?

 

What color are the plugs?

[hang_510]

What the hell could cause more fuel to come out of only one cylinder!?

 

timing / IN valve out of adjustment :confused: