Printable Version of Topic

Posted by: KaptKaos Nov 17 2007, 10:31 PM

I have 44 idfs. The venturis are 32s. I have read that the 32 is the smallest for the 44s. Is that the case? I thought I saw 28s, but I am not sure.

Does anyone know for certain?

If it's possible, does anyone have 28 vents for 44idfs?

Please let me know.

Thanks!

Posted by: Aaron Cox Nov 17 2007, 10:38 PM

make some on a lathe?

tried john at aircooled.net?
CB performance?

IIRC 28 is only available in a 40 OD

Posted by: Twystd1 Nov 17 2007, 10:39 PM

I have seen aftermarket 28s and 30s for the 44 IDF. (Custom)

And YES to your question. The smallest venturi that weber made for the IDF is a 32. (To my knowledge) Thats the smallest you can buy from the weber parts guys anyway.

Gimme us list of your existing jets and E tubes again. I forgot what ya had.

Clayton

Posted by: Aaron Cox Nov 17 2007, 10:40 PM

for a 44 IDF that is.....

Posted by: KaptKaos Nov 17 2007, 11:05 PM

emulsion tubes F11
Air Correction 190
Mains 145
Venturis 32
idles 0.5

Posted by: Aaron Cox Nov 17 2007, 11:06 PM

LOL on the mains.....

i have some 135's or 130's you can try before you order some.

Posted by: Twystd1 Nov 17 2007, 11:57 PM

Thanks Aaron. Dats what I meant........ 32s for 44s.

AA is right about your jetting. You SHOULD borrow AAs jets. They are closer to what you need.
And go down on your airs. 170 -180s maybe.
Maybe try 40s or 45s for your idles.

Stay with your F11 tubes.

Whadya think Aaron?? That sounds like a good starting point to me.

Clayton

Posted by: euro911 Nov 18 2007, 01:40 AM

I have some .45 idles we can try out Joe ...

Posted by: Aaron Cox Nov 18 2007, 11:01 AM

wouldnt you step up a size on the air correctors clayton?

Posted by: KaptKaos Nov 18 2007, 03:49 PM

So I went out and checked a few things.

First, I checked the timing. It's an 050 and its about 5 degrees at idle and about 28 degrees at 3500 rpm. It seems to be advancing properly, so that's good. I haven't dropped in the Mallory yet, as it is a "loaner" and I don't want to blow it up.

I also checked the compression. All 4 are between 110 and 120. It's an old gauge that I haven't used in years, so I am not sure that it reads correctly, but they are all consistent.

After doing this, I took it for a quick spin around the block. It just won't pull above 4000. I am worried that those 32 vents are just too big. I figured it would clear up at some point, but it really doesn't. I plan to try new mains and ACs, but I am starting to worry that the carbs might need to be smaller.

Posted by: Twystd1 Nov 18 2007, 11:42 PM

You can tweak that 050 dizzy to be at 12 - 15 degrees initial. That will help the bottom end immensely.

Why it won't rev past 4K is another story.

Could be ignition, could be carbs, could be valve springs, could be shit gas or a compendium of any of the above.

Which one ya wanna start with?

C

Posted by: Aaron Cox Nov 19 2007, 12:36 AM

the carbs should atomize BETTER with more velocity (higher engine speed)

too retarded of timing? but you checked that.

im gonna guess ignition....
does it start lurching at 4grand? (rev limiter rotor? lol)

valves adjusted right? compression check says yes.... one is not open.

think small cc race motors that pull 7-8000 rpm. They can use the big carbs to make the power high up.... i would think your situation would get better with more rpm.

hmmmm......


i am gonna guess it is ignition related.

Posted by: euro911 Nov 19 2007, 01:41 AM

Double check your dwell angle first. If its not right, everything else will be out of whack.

Do you wanna make your dizzy timing adjustable from the driver's seat?

Posted by: Twystd1 Nov 19 2007, 01:45 AM

Aaron to answer your air correction jet question.

Bigger airs mean you will bring in the main jets FASTER. (earlier)

I know thats counter intuitive. Yet thats the way they work.
It's less a fat or lean thing. It's more of a transition timing event.

This is one of the things you can do if you get a flat spot in the transition from idles to mains. Try a bigger air corrector jet.



FOR JOE,
I think you may have an ignition problem of some sorts. (Like AA said)
You could Index that Mallory correctly and throw it in. And see what happens.

OR:

Ya might want to swap your coil and rotor/cap and see if that makes any difference.


If it is carb related. And based on what you stated above.
The next approach might be to do the following:

If you are running out of steam at 4K. Try a bigger main jet.

NOTE: A bigger main jet doesn't really affect the lower RPMs. It will affect transition a bit after most of the idle circuitry cuts off an you are running on the Mains only. So a bigger main won't make any difference down low.
If a bigger main helps the problem. just keep going up in main size.

NOTE: If ANY of your air bypass screws are open. CLOSE EM. And start a fresh tuning session..


Clayton


C

Posted by: Aaron Cox Nov 19 2007, 10:04 AM

pertronix dont have dwell angle issues..... LOL

Posted by: Aaron Cox Nov 19 2007, 10:06 AM

clayton... he has a 145 main. HUGE for a 1.9

could he be getting SOO much fuel that it just wont burn it all?


Joe - what are your accel pump squirters set at?

Posted by: Joe Ricard Nov 19 2007, 11:39 AM

Aaron quit hinting around the bush.

YES HIS MAIN JETS ARE TOO BIG. You will not make more power till you step down the main jet size to 130 with a 180 to 200 Air correction.

I bet you were poofing fire balls out the tail pipe when let off.

the 44's are probably too big to make the most out of the engine but it will run and the faster he goes the better it will run.

Lean it out and watch it bounce off the rev limiter.

Posted by: euro911 Nov 19 2007, 12:38 PM

He's running a '050' with points right now ...

You can see and smell raw fuel coming out of his tailpipe. Light a match to it and you'll have a flame-thrower

At high revs, balls of mist float up out each of the velocity stacks too

Posted by: KaptKaos Nov 19 2007, 02:43 PM

I just lobbed John @ Aircooled.net an email asking for his advice and part numbers. I will let you all know what he comes back with.

Mark, might want to try those .45 idles. I may come to class tomorrow. Might drag Dad along too We'll see.

Posted by: KaptKaos Nov 19 2007, 03:07 PM

Update.

John from Aircooled.net wrote me back and said:

I guess he was talking to Aaron

So I will order the idles, the mains and ACs now. He's got a great policy, so I can try these out and see how they go.

Any input or should I just place the order? Please let me know.

Thanks!

Posted by: Joe Ricard Nov 19 2007, 03:27 PM

I think you know what you need to do.

Posted by: Aaron Cox Nov 19 2007, 08:21 PM

you should be close

(40's would be better LOL)

Posted by: euro911 Nov 19 2007, 10:22 PM

Thats cool that you'll be able to 'trade back' the jets if they ain't right.

IIRC you have .55 pump nozzles now

Well, you'll have .45, .50 & .55 idles to play with too.

I'm dealing with a pretty a bad cold right now, so not sure if I'm going to class (or even work for that matter)

Posted by: KaptKaos Nov 19 2007, 10:39 PM

Dad and I are going to the car show downtown, so I think he done with cars by 5:30 PM tomorrow.

Posted by: rhodyguy Nov 20 2007, 08:51 AM

it might be considered polite to purchase from the firm that took the time to give you the information. spring for the asap delivery via USPS if available. the return policy sure seems fair enough.

k

Posted by: KaptKaos Nov 20 2007, 10:54 AM

Done and done.

Posted by: KaptKaos Nov 21 2007, 05:10 PM

I got the jets from AirCooled today. Dropped the mains and airs in and there is an improvement up top. It's still a dog down low.

I hope to put the idles in tomorrow or Friday. Any hints or advice?

Posted by: SGB Nov 21 2007, 10:14 PM

thats what should happen. the bottom end is controlled by the idles.

one hint- make sure the idle jets are snug in the seats- be careful those little tabs will break. Just move em around (all four jets with the seats they sit in) until you get the four best fits.

Posted by: rhodyguy Nov 21 2007, 10:43 PM

after presetting the idle air mixture screws, and running them in at idle, aprox how many turns out until each cyl smooths out? abrupt changes without turning them out very much, or do you have to run them way out until things calm down?

k

Posted by: Twystd1 Nov 21 2007, 11:03 PM

TYPICALLY 1.5 - 2 turns out gets ya there if you have the right idles jets and NO intake leaks.

Clayton

Posted by: euro911 Nov 21 2007, 11:05 PM

Its really 'play it by ear' (although watching a tach helps).

There's a very narrow range with the idle mixture settings. That old '2-1/2 turns out' theory just assures you're getting fuel into the cylinders ... a good starting point, not 'Bible'.

Open and close the needles in small increments a few times to get them where you believe they're right, then go back and do it again (all on a warm engine).

Next, drive it for 10 ~15 minutes (like out on that nice stretch on Lincoln Blvd) and check the mix again when you get back. Note your performance (increase/decrease) and/or any irregularities when test driving ...

Posted by: KaptKaos Nov 22 2007, 01:54 PM

So I put in the idles. Big difference. However, it may not have been the sizes of the idle jets (went from 50s to 55s), but there seems to have been 2 issues. 1) One of the idle jets was broken. One of the flanges that held it into the screw was missing. Not sure how that happened. I didn't check all of them when got the carbs. 2) The driver's side were not screwed in very tightly. There may have been some air leaks there.

Now the car idles way high.

I took it for a spin, and it definitely has more go. Which is good. I need to put in my breather box, because it burped oil from the tower all over the inside First time that's happened. Glad I didn't run it long.

Also, I am a little concerned about the health of the engine. It seems to be smoking a lot. I'll clean up the oil, mount the burp box, adjust the idle and see how it goes from there. I'll do a leakdown test next week to see if its the rings (hope not).

Anyone have a pic of the 44 idfs that shows which screws adjust the idle? The book I have isn't very clear.

Getting closer!

Posted by: Aaron Cox Nov 22 2007, 02:09 PM

on the outboard side of the carbs, the idle mixture screws are the ones with springs on the shaft (to preload them so they do not get loose)

In is lean.
Out is rich.

(first warm up the engine... get it to idle)

1. Disconnect Linkage
2. Measure flow of each barrel.
3. They should be close/exact. (especially on the same carb!)
4. when they are all exact flow, you can start messing with idle mixture
5. start with one carb and one barrel. Slowly turn the mixture screw INward about an 1/8 turn at a time. The idle should go up (leaner) and eventually that cylinder will die (too lean)
6. Back out the adjuster in the same way about an 1/8 turn at a time, until you are just past that high idle spot. (just a tad rich of the high idle)
7. Do this with the other 3 barrels.
8. Then you can adjust the idle stops to make both carbs flow the same

At the end of this, you will have a nice idle mixture, and all your adjuster screws SHOULD be around the same # of turns out, and should all flow the same.

If there is a flow differential between the 2 barrels on one carb, you *CAN* adjust this with the air bleed screws.

I have stressed this, but i IMPLORE you to buy the CB performance book on Weber Carbs. Mine went missing but it teaches you everything about IDF carbs.

once you understand what each part does, you ca understand how the changes work

claude does a great job of explaining

Posted by: KaptKaos Nov 22 2007, 03:03 PM

But it's much more fun to ask you for help

Posted by: Aaron Cox Nov 22 2007, 03:24 PM

for you....




LOL

Posted by: KaptKaos Nov 26 2007, 07:28 PM

Ok, I tried to get the carbs synched. I don't want to mess this up, so I took my time and got to a stable point. Here is where I am at:

1) All air corrections are in full, so they should be off.

2) All air/fuel screws are 3 turns out, which should be a little rich.

3) Idle is at about 800 rpm right now.

4) Driver's side stacks are pulling 6 and 4.5 on the carb sync tool.

5) Passenger side stacks are pulling 9s front and rear.

Motor was hot, so I didn't pull the plugs to see if it was running rich or lean. I have shop class tomorrow and we have an exhaust meter there to tell me if it's rich or lean, so I will try it there.

I tired several times to get the driver's side barrels to come up on the sync tool, but no luck. I didn't want to lean it out too much without a good way to tell how lean it is running. So I will try again tomorrow.

Any hints or tips appreciated. At worst, I should be able to make it to Joe's Saturday, but I may have to skip the fun run until it gets tuned.

Posted by: Aaron Cox Nov 26 2007, 08:59 PM

back off the idle stop screw on the PS carb to get it down to 6

Posted by: euro911 Nov 26 2007, 09:27 PM

I chided spoke with Cap'n Cal Joe on the phone earlier this evening ... discussed that very issue ...

... even sent him one of these yesterday

Where's the :ball-scratcher: gif




Attached image(s)

Posted by: Aaron Cox Nov 26 2007, 09:30 PM

buy the damn cb book already joe.....

Posted by: KaptKaos Nov 26 2007, 09:56 PM

Lighten up Francis

I'll buy the book. It's not like its going to get here by tomorrow night now is it?

And yes, I think I have the info I need to at least get it close. We have an exhaust sensor at shop class, so maybe I can see if it is running too rich or too lean. Anyone know what that would look like?

Posted by: KaptKaos Nov 26 2007, 10:00 PM

This the right one?

http://www.cbperformance.com/catalog.asp?ProductID=4

Posted by: Aaron Cox Nov 26 2007, 10:09 PM

yes.

order two. I will buy one. I loaned out or lost my other one.
Paypal ya.

Posted by: euro911 Nov 26 2007, 10:09 PM

John will have a chart of 'allowable' emissions at the shop

Posted by: Carlitos Way Nov 26 2007, 11:53 PM

My only suggestion is... if you're trying to adjust carbs... make sure you start with the basics first.

Check valve clearance first and foremost.
Double-check spark plug gap
Make sure linkage moves freely.

Posted by: rhodyguy Nov 27 2007, 08:12 AM

have these carbs been COMPLETELY rebuilt? there are a number of very small o-rings that can complicate things if they're in poor condition. specificly, at the idle jet ports and under the idle air mixture screws. are those flow #s with the linkage hooked up? if so, disconnect the linkage where they attach throttle shafts and recheck your flow numbers. there should not be that large of a dif side to side. the pass side barrel #s should read closer than the 1.5 dif. as aaron suggested, with the linkage connected, back the idle speed screw FULLY off the stop on the pass carb, it will just be at a neutral rest at this point. recheck the flow side to side. still way off? you will need to adjust the droplink to bring it in. simply running idle speed screws in and out with the linkage connected, can push the opposite side screw of the stop.

are you using cut washers under the carb to manifold nuts?

k

Posted by: KaptKaos Nov 28 2007, 12:51 AM

I ordered the books Aaron.

Now, after saying that, I took a swing at them again tonight. I got them pretty well balanced side to side. However, while I was doing that, I noticed that my driver's side carb (the one I was having the most trouble with) was squirting fuel into the vent, while the passenger side was not. Might I have a float issue?

Got an exhaust analyzer, and leaned them out. but they're not consistent.

I will likely richen things up and bring it to Joe's Saturday. I'll likely go through 10 gallons of gas to get there

Posted by: euro911 Nov 28 2007, 01:53 AM

I'm going to try to get to the shop Thursday night. We can take a peek at the carbs if you want to bring the car in

Have you checked your pump diaphragms? ... also, are your pump jets cinched tight in the bowls?

If you don't want to wait till then, check those items, and here's the float setting guide:


Attached image(s)

Posted by: euro911 Nov 28 2007, 01:59 AM

PS, you have to go on the run Saturday ... if you're still running rich then, you'll just have to be the last car in line

Posted by: rhodyguy Nov 28 2007, 06:48 AM

so the driver's side is leaking out of the pump jet at idle? pulsing out of one of them or both? one of my 40s was doing the same thing only on the pass side. i "just" could dial it out with the threaded rod but it wouldn't run without snapping back throught the carb. a full meal deal rebuild may be in order. i opted to send the 44s to Air Cooled Engineering. they are going on the car this am.

Posted by: KaptKaos Nov 28 2007, 11:52 AM

Unfortunately, I can't make it to class Thursday night. Wife has a meeting she needs to go to.

I will likely richen it up and just drive to Joe's. I don't want to over-stress it if I can avoid it.

Oh, can you call me. I may need your help Thursday or Friday afternoon if possible. I have something to pick up

Posted by: Aaron Cox Nov 28 2007, 01:34 PM

check your floats....

Posted by: KaptKaos Nov 28 2007, 01:55 PM

I'll do that as soon as I get my book.

Posted by: Aaron Cox Nov 28 2007, 05:24 PM

told ya weeks ago

marks pic shows ya how.... but ok

Posted by: KaptKaos Nov 28 2007, 06:21 PM

I get about 4 hours during the week to do car stuff. Sometimes less. On the weekends, I'm lucky to get 3-4 hours unless I plan it out. Unfortunately, I am losing 2 of my 4 hours this week because the wife has a meeting. So the time that I could make these changes got taken away from me this week.

The only other chance I have this week is Saturday