ID assistance needed - Webers Options

[william1764]

Which is the idle jet? What do all these screws do - i count 5 per side? I referenced an old Weber diagram but can't figure out. (IMG:style_emoticons/default/headbang.gif)

Changed the plugs yesterday - photo also attached. This is after 300 miles +/-(IMG:style_emoticons/default/WTF.gif) Still have carb popping and jumpy idle at 3-4k along with sluggish at lower RPM. Want to clean idle jet once I figure out were the heck it is (IMG:style_emoticons/default/confused24.gif)

[sww914]

The idle jets aren't in your picture. They're the 2 brass screws just below the fuel inlet. When you unscrew them there are 3 pieces to each one. The jet holder, the jet, and the O ring. Don't lose the O rings, they might stick to the carb body or maybe stay on the jet holder. Pull the jets out of the holders and blow through them from the inside out.
The idle mixture screws are shown in your picture, they're the 2 screws with springs on them. Redline Weber has a decent adjustment guide on their website.

[william1764]

The idle jets aren't in your picture. They're the 2 brass screws just below the fuel inlet. When you unscrew them there are 3 pieces to each one. The jet holder, the jet, and the O ring. Don't lose the O rings, they might stick to the carb body or maybe stay on the jet holder. Pull the jets out of the holders and blow through them from the inside out.
The idle mixture screws are shown in your picture, they're the 2 screws with springs on them. Redline Weber has a decent adjustment guide on their website.

Thanks Steve. Fuel inlet location??? I hate to waste everyones time with such elementary questions - I'm freakin' 47 and attempting to learn how to perfom some of this stuff myself for the 1st time. Will Redlines site help me with my identification issues;-)

[william1764]

Found them! Above the screws in the pic - one on each side of the "inlet". Thanks Steve (IMG:style_emoticons/default/pray.gif)

[VaccaRabite]

You are rich at idle. Look at the jets and see if they are clogged but you may have compunding problems.
Also let us know what size they are. Looks like you may be able to go down a size. Do all four plugs look like that?

Aren't carbs great? I am still futzing with mine after drivIng the car for two years.

I bet you are getting the hesitation from fouled plugs.

[william1764]

I friggin' did it and in complete awe with myself (IMG:style_emoticons/default/smilie_pokal.gif)

seriously - i located jets thanks to steve, blew them out and re-installed. Bam...she ran sweet. Carb popping/hesitation gone. Combined with the recent exhaust leak repair she's running the best she ever has. I got estimate from local shop to fix popping/hestiation issue on Friday for $1,000 bucks...not! Now i can spend that $ on refinishing wheels and other stuff.

I know this sounds silly but serioulsy - i'm the most non-mechanical person i know. Everyone told me you better learn to turn a wrench or you'll go broke on these cars... plus you'll know them much better if your perfroming the work. In the last month I've performed the following; replaced exhaust gaskets, plugs, front pads and now idle jets! Next - valve adjustment (IMG:style_emoticons/default/aktion035.gif)

Thanks for the help all (IMG:style_emoticons/default/beerchug.gif)

[william1764]

You are rich at idle. Look at the jets and see if they are clogged but you may have compunding problems.
Also let us know what size they are. Looks like you may be able to go down a size. Do all four plugs look like that?

Aren't carbs great? I am still futzing with mine after drivIng the car for two years.

I bet you are getting the hesitation from fouled plugs.

zach - how can you tell what size the jets are? I plan to call the shop that performed the carb rebuild last summer to see if they have record - not on work order. I agree that i'm running rich - you can smell it not to mention the fuel mixture i get out of the exhaust on initial start. I guess that will be my next project.

[GeorgeRud]

I'm not sure about yours, but there are very small identifications stampings on my jets that tell you the size. However, in the past, people also used to drill out jets to change sizes, so you may be unable to tell for sure if the car was carbed when you bought it.

From the plugs, it certainly does look like you're running quite rich and could stand to go down a size or two on your jets at least.

There are quite a few books on tuning Weber carbs. They really are not all that complicated when you simply learn the various circuits that they have.

[VaccaRabite]

(IMG:style_emoticons/default/agree.gif)
Easiest way is to pull one of the idle jets again and look for the little stamping. if it says "55" try a 50 (my guess on what its going to say).

Reading plugs with modern fuels only tells you the mix at the last moments of operation. So you can look at that plug and read anything more about it then idle a second or two from when you shut off the car. But, lots of driving gets done on idles - for street cars it can be a whole lot.

Call Peek Performance for your jets. they are somewhat local to you, and are very quick with shipping. Even to me in York PA, my order is at my done usually withing 48 hours.

Good job, BTW! These little cars are fun to work on, and it warms my heart to see a guy start doing it.

Zach

[william1764]

(IMG:style_emoticons/default/agree.gif)
Easiest way is to pull one of the idle jets again and look for the little stamping. if it says "55" try a 50 (my guess on what its going to say).

Reading plugs with modern fuels only tells you the mix at the last moments of operation. So you can look at that plug and read anything more about it then idle a second or two from when you shut off the car. But, lots of driving gets done on idles - for street cars it can be a whole lot.

Call Peek Performance for your jets. they are somewhat local to you, and are very quick with shipping. Even to me in York PA, my order is at my done usually withing 48 hours.

Good job, BTW! These little cars are fun to work on, and it warms my heart to see a guy start doing it.

Zach

Thanks Zach

[maf914]

William,

There are several Weber manuals available that will help you with identification of parts and tuning/rebuilding. I like the Haynes Weber manual, but I am not sure if it is still available. You might check the Amazon link below for some of the available books.

http://www.amazon.com/s/ref=nb_sb_ss_c_2_1...eber+carburetor

I have also used the old Chilton/Clymer 914/914-6 manual since it covers the 916-6 and its Weber carbs. Although these were triple throat Webers they are close enough to dual throat IDF's that most procedures are the same. Good luck with your tuning.

[william1764]

William,

There are several Weber manuals available that will help you with identification of parts and tuning/rebuilding. I like the Haynes Weber manual, but I am not sure if it is still available. You might check the Amazon link below for some of the available books.

http://www.amazon.com/s/ref=nb_sb_ss_c_2_1...eber+carburetor

I have also used the old Chilton/Clymer 914/914-6 manual since it covers the 916-6 and its Weber carbs. Although these were triple throat Webers they are close enough to dual throat IDF's that most procedures are the same. Good luck with your tuning.

TX

[HarveyH]

One thing that can't be reiterated enough:
In the Weber carb, everything effects everything else. Make one change at a time and see what happens over a range of driving conditions,

The Idle Adjustment Screw only controls the mixture at a static idle. (If the carb is set up right and the throtle plates are positioned where they should be)
The Idle Jet controls the mixture from just off idle to about 3000 RPM
The Main Jet controls the mixture from about 2000 RPM up. (Notice the overlap with the top end of the Idle Jet)
The Air Correction Jet modifies the mixture curve of the Main Jet starting around 4000 RPM and going up. (The higher the RPM, the more effect)
Emulsion Tubes are magic and somehow effect the overlap ranges of the other jets. They apparently do other things too, but I don't think I understand it...

Research, Learn, Think, Make a Change, Observe, Think, Repeat.

[maf914]

There are several Weber manuals available that will help you with identification of parts and tuning/rebuilding. I like the Haynes Weber manual, but I am not sure if it is still available.

William,

I just did a little search and I found this copy of the Haynes Weber manual. I have bought several books, new and used, through this web site and have had no problems. This is a used book, but a good price, $12 + $3 shipping = $15.00. Act quickly if you want it.

http://www.abebooks.com/servlet/SearchResu...p;x=12&y=13

[Razorbobsr]

I friggin' did it and in complete awe with myself (IMG:style_emoticons/default/smilie_pokal.gif)

seriously - i located jets thanks to steve, blew them out and re-installed. Bam...she ran sweet. Carb popping/hesitation gone. Combined with the recent exhaust leak repair she's running the best she ever has. I got estimate from local shop to fix popping/hestiation issue on Friday for $1,000 bucks...not! Now i can spend that $ on refinishing wheels and other stuff.

I know this sounds silly but serioulsy - i'm the most non-mechanical person i know. Everyone told me you better learn to turn a wrench or you'll go broke on these cars... plus you'll know them much better if your perfroming the work. In the last month I've performed the following; replaced exhaust gaskets, plugs, front pads and now idle jets! Next - valve adjustment (IMG:style_emoticons/default/aktion035.gif)

Thanks for the help all (IMG:style_emoticons/default/beerchug.gif) Bob here, going through much the same prob, watching your thread!!!

[Razorbobsr]

(IMG:style_emoticons/default/agree.gif)
Easiest way is to pull one of the idle jets again and look for the little stamping. if it says "55" try a 50 (my guess on what its going to say).

Reading plugs with modern fuels only tells you the mix at the last moments of operation. So you can look at that plug and read anything more about it then idle a second or two from when you shut off the car. But, lots of driving gets done on idles - for street cars it can be a whole lot.

Call Peek Performance for your jets. they are somewhat local to you, and are very quick with shipping. Even to me in York PA, my order is at my done usually withing 48 hours.

Good job, BTW! These little cars are fun to work on, and it warms my heart to see a guy start doing it.

Zach

Cute trick...... Horn blows when turn sig is blinking??? This is a first, ideas? Bob

[william1764]

One thing that can't be reiterated enough:
In the Weber carb, everything effects everything else. Make one change at a time and see what happens over a range of driving conditions,

The Idle Adjustment Screw only controls the mixture at a static idle. (If the carb is set up right and the throtle plates are positioned where they should be)
The Idle Jet controls the mixture from just off idle to about 3000 RPM
The Main Jet controls the mixture from about 2000 RPM up. (Notice the overlap with the top end of the Idle Jet)
The Air Correction Jet modifies the mixture curve of the Main Jet starting around 4000 RPM and going up. (The higher the RPM, the more effect)
Emulsion Tubes are magic and somehow effect the overlap ranges of the other jets. They apparently do other things too, but I don't think I understand it...

Research, Learn, Think, Make a Change, Observe, Think, Repeat.

thanks for the explanation harvey - i wondered the differences and relationships between the various jets

[william1764]

ok...pulled idle jet and the marking is 50. i 'm told, and it would seem i'm running VERY rich. when she starts up there is what appears moisture (maybe fuel) that spits out the tail pipes when rev'd. also smokey (equally) out both exhausts. i'll run around the block a few times until hot and when i return the smoke is gone and no more moisture out pipes.

i assumed the 50 was on the smaller end of the scale based on other post so why am i running so rich? can i/should i go smaller than 50? what else would cause her to run rich?

other than the above she does seem to be running well however i did notice the jet appeared partially clogged already (just blew them all out). I assume i need to change/add fuel filter or something.

[McMark]

Moisture coming out the tail pipe during warm-up is water that condenses. Normal.

I haven't seen anything about what size engine this is or what size webers these are. As someone mentioned before, the carbs are part of a complex system. We need to know all the info to help. One single piece of info by itself doesn't help.

If you have crap in your fuel system, check the fuel tank for rust by opening the filler cap and looking down with a flashlight. Fuel filters are not reliable and I've seen amazing chunks of crap get by 3 or 4 filters in series. Filters are not there to clean up a dirty fuel system. Clean the fuel system correctly, and install a filter for the last 0.5% of crap that you can never get rid of.