OK, I'm going to mess with my carbs for the first time this afternoon, with help from a friend who knows what he's doing... The car runs good as is, but I know it's rich.

The Stats are:

stock 2.0, webcam, dual weber 40's, Mallory dist, with MSD.

I have NO idea what's in there now as far as jets, venturis ect.

I live at 5500 Ft elevation. The car's previous owner was not much above sea level...

Any good guess on what to start out with?

Ferg

Something tells me that you are going to start out with some carb cleaner and a good car wash .

Wear protection if it's your first time.

You guys are funny


Anyone got "real" answers?

Ferg

Just throw a weber single progressive on there, that should fix it up, make her scoot!! Sorry... couldnt help myself...I dont know, lol.

Hey Ferg,
Here is some real and sound advice, call CB Performance and tell them what you have, they will be able to tell you everything you need to be running for the best performance. 1-800-274-8337 Ask for Marrianne? I think that was her name, really sharp lady.

This guy could probably help you with your CARB problem.
Personally, I think you look fabulous


sorry, last one.

Stuff of interest to you:

http://www.914world.com/bbs2/index.php?sho...&hl=jetting

http://aircooled.net/gnrlsite/resource/articles/jetting.htm

http://www.914world.com/bbs2/index.php?sho...2&hl=webber

http://www.redlineweber.com/html/Tech/Table_of_contents.htm

http://www.914world.com/bbs2/index.php?sho...1&hl=webber

This might get you started..

thanks Scott and Jared

Greg

I think Hinkle was supposed to be the local Carb expert.
Gint ain't too shabby either, but he's sometimes grumpy
Then there's El Frio (ben). He's actually a mechanic now.........

take a picture of your plugs when you get started and post the various #s. with mine, sim setup except fi cam and the pro e coil. i've found my car seems to perform much better running mid-grade fuel. i tried a tank of premium on my last trip and it was way fat. black smoke on hard accel in the upper rpm range. back to m-g and the smoking went away, the idle improved, and the mpg went up. i would try try the fuel both ways before settling on the jetting. my guess is thin air at 5k+ will have some effect too. check with gint to see what he's currntly running in his car. it might be a good baseline. recheck your timing first. don't blow up the optical sensor in the mallory.

k

Hinkle is in hiding, and likes to smoke while working around gas

Gint's only grumpy to you

And Ben is certainly qualified but lives down by you in Castle Rock or something. He most likely thinks it's Wednesday anyhow

Ferg

Do a search for "carbs".

I did, 21 pages, started to weed through some of it, but found nothing comparable to my elevation.

I'll report what I learn this afternoon later. getting ready to bolt out of the office now.

Ferg

Enjoy!

http://www.carburetorclinic.com/tech_articles.htm

Roger

For cross reference-
my 1973 2.0, dual 40ida webers, mallory dizzy, and hydro webcam likes:
idle jets: 55
main jets: 120
Air corrector jets: 200

Ok, well I did not get the mallory installed like I had hoped, but I did some carb tuning and now know at least what I have.

Main: 115

Emulsion: F11

Air: 200

Idle: 50

We didn't change anything, just sync and cleaning.

My reverse switch was leaking and broke off the moment I put a wrench on it, so that ate up some time. Luckily the rest came out easy.

I need to order a new coil, plug wires ect, and hope to do the mallory next weekend.

Ferg

I told you

I've tried a few others:
50 idles ran hot.
130 mains stumbled
180 airs ran hot too

That's pretty conservative jetting for a 2.0L. That's the identical setup to the last 1.7L I did and it ran great at 2200ft, but was a little lean down at sea level. So your car would probably be very lean at sea level. You might be able to get away with your current setup at elevation, but you may want to try some 120 or 125 mains to see how it likes them. I certainly wouldn't jet it down much further as you probably aren't running as rich as you think.

I have a 2.0L carbed engine that was running your jetting at 2200ft to pass emissions and of course it was pretty lean. In fact it was still too lean even at 4500', though not as bad .

If you are running lean (and you may very well be), it would explain some of the high temps you were experiencing.

That's also pretty close to stock "out of the box" jetting for IDF's. Except the 50 idles. I'm running 55's, can't remember what else...

Here's my method, as described about three years ago, and how I've done it for a long time. This is how I do the three barrels, and it'll work fine on the 2 barrels too.

>>
Assumptions: the carbs have the optimum jet and venturi package (good luck on this one), the float level in the carbs is correct, the cams are correctly timed, the valves are properly adjusted, the ignition timing is dead on, you have the proper spark plugs for your engine, the linkage is good, the fuel is good, the engine has good compression.

Remember that the mixture and air bypass adjustment screws are precision needle valves, not head gaskets. Use your fingers to tighten them, not your fist.
Start and warm up the engine.
Make sure the two drop links for the throttle linkage are exactly the same length, and disconnected. You can use a 8mm thin igntion wrench to snap them off.
Turn the mixture screws all the way in and then 5 half turns out.
Turn the air bypass screws all the way in.
Turn the idle speed screws out til it just touches, and then in 5 half turns.
Put on your hearing protection and start the car.
Use your STE and find the barrel that pulls the most. We'll call this one baseline.
Balance the barrel in the other carb that pulls the most with the idle speed screw. (if you have a Uni-syn, give it to someone you don't like and purchase a STE airflow meter)
Go back to the other carb, with the baseline barrel. You will have one all the way in, then use the air bypass screws and balance the other two barrels.
Go to the other carb and do the same thing.
Snug the jamb nuts on the air bypass screws.
All six barrels should pull the same amount of air at this point, if not repeat air adjustment proceedure.
Snap the throttle linkage drop links back on the carbs. If the idle changes then you need to barely adjust the linkage mounts so snapping the drop links on, doesn't change the side to side idle balance.
Use the hand throttle or a vice grip and rag to lock the linkage between 1400 and 1800 rpm.
Start back at the baseline barrel and adjust the mixture screw in or out, to get the smoothest running and highest idle, then turn it in 1/4 turn.
Do the same with the five other mixture screws.
If you have to turn the mixture screws more than two turns either way, you've got the wrong jets.
Recheck side to side and individual air balance, adjust as needed.
Road test the car.
If you get snapping and popping out the intake, it's generally a lean condition.
If you get heavy exhaust fumes, or pboofing out the exhaust it's probably too rich.
If you get a flat spot or popping out the intake at between 2800 and 3200 rpm, you probably need larger idle jets.

Another good diagnostic trick is to back out the idle jet holders just enough to make the engine stumble a little. If you back it out and nothing happens, then that jet or passage is clogged. Be careful not to back the jet carrier out more than one full turn or you'll have raw fuel leaking out.

That's a rough, five minute draft of my carb tuning proceedure, hope it helps!

If it goes good it should take about 45 minutes, if not about three years (until you get your jet/venturi pkg figured out).

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