Help with Weber 40s

[Dawskip]

Hello all,

 

I’m a e30 guy and recently moved into the 2002 world. I’ve acquired a 2002 with a beef cake of an engine, included in that are the Weber 40 DCOE. I’m not a carb guy, in fact this is the first carbureted engine I’ve owned, however I know that something isn’t right!

 

 

I’ll attach a picture, but to describe it — the carb linkage is being held up with a spring. Without it the carbs basically operate as if they are open, I’m not a expert but I feel like this spring isn’t the correct / safest way to operate the vehicle and was wondering if someone could give me some pointers on the correct setup? 

[AceAndrew]

It's a throttle return spring, and although janky looking, it will work as intended.  Those are some slick old Italians, very cool.

 

My suggestion

-ditch that throttle linkage and run this one.  That particular linkage likes to slip and can be a bother (especially for a new recruit on the cool kid carburetor bandwagon).  You can see a similar spring in this kit (along with a cool inline one).

-ditch those filters and run short stacks with socks.  No stack filters make low end idle tuning worse than it needs to be. 

-edit:  Also, those look like O-ring style soft mounts.  Ditch them when reasonable.  They will leak.

 

[Son of Marty]

+1 on Andrews post, your likage will work but it's hard to keep in sync, how does it run now?

[Dawskip]

1 minute ago, Son of Marty said:

+1 on Andrews post, your likage will work but it's hard to keep in sync, how does it run now?

running good now tbh, struggled at idle on start up but other than that no issues. 
 

that being said, the PO did have that rare issue of carbs being stuck open, figured something wasn’t great with the current setup. 

[man_mark_7]

I will 2nd, 3rd, and 4th the suggestion to go with the Hal Boyles carb linkage. So much easier to get working right than the system you are currently running. Been there, ditched that.

 

mark

[TobyB]

My learning experience with DCOEs was made far better by the acquisition of 2 things-

 

a synchrometer

http://www.redlineweber.com/html/application_guide/redline_synchrometer.htm

 

and a wideband oxygen sensor, with gauge.

https://www.innovatemotorsports.com/

 

Oh, and then the internet.

https://www.lainefamily.com/images/WeberTuningManual.pdf

 

Not to undercut Hal's business, but it's pretty easy to get an adjustable center link, and then

use the overarm parts you have to make a far better linkage for not much effort or money.

That's the 4th thing I did with mine, after the dual overarms refused to stay in sync.

Make sure each carb closes itself (on the pump spring) when disconnected from the main linkage.

Then add 2 separate springs to the main linkage.

 

t

 

[halboyles]

10 hours ago, TobyB said:

Not to undercut Hal's business,

Not to worry Toby, we are barely keeping up with demand right now with no advertising (except for these random thread highjackings!).

 

The reasons are simple:

Our linkage system is a bolt on solution, no fabrication required.

It is based on the original 2002ti linkage system, it looks "OEM"

Synchronization is all done on the carbs, not the linkage

It is rock solid and requires no maintenance

It is recommended by everyone who has one!

 

Oh, and did mention it is shiny!

 

 

 

h- appreciates the segue!

 

[Son of Marty]

Hal, My 74 got twin webers and the factory linkage back in 74, I can't tell the factory stuff from yours, and my linkage has been bullet proff over 250k miles. The trouble with the "twin post" set up as shown is the engine rocking pushes on the throttle rod where the single post reduces this until it's not noticeble. 

[Pdxguy]

Shiny increases horsepower by 7.28%. Fact

[Dawskip]

7 hours ago, Pdxguy said:

Shiny increases horsepower by 7.28%. Fact

Bored to a 2.2

292 cam

Shiny bits

 

probably at AT LEAST 1000hp. 

[Pdxguy]

33 minutes ago, Dawskip said:

Bored to a 2.2

292 cam

Shiny bits

 

probably at AT LEAST 1000hp. 

Fact

[Dawskip]

On 6/25/2021 at 12:23 PM, TobyB said:

Not to undercut Hal's business, but it's pretty easy to get an adjustable center link, and then

use the overarm parts you have to make a far better linkage for not much effort or money.

That's the 4th thing I did with mine, after the dual overarms refused to stay in sync.

Make sure each carb closes itself (on the pump spring) when disconnected from the main linkage.

Then add 2 separate springs to the main linkage.

 

 

Any thread on this somewhere? Would like to explore this option if its not too difficult / saves me money

[TobyB]

Well, see, that's why Hal's doin' so well-

 

you'd need to go to a vendor, find just the center link part, and then get the other little

bits and tabs to make it work.  I think I got mine from Redline back when they had a print catalog-

I picked out the center adjuster, got 2 extra tabs, then filed and modified and extended to get it to work.

 

t

[Stevenc22]

I have the same linkage as you. Those turnbuckle style connections to the carbs gum up easily and stick the carbs open. Using that big return spring just makes your pedal very heavy. I converted those turn buckles to 8mm ball connections and that solved all my sticking problems. I will post pictures when i get home.

 

You can also consider Hal's kit. Either way you should make changes to your current linkage.

[halboyles]

9 hours ago, TobyB said:

Well, see, that's why Hal's doin' so well-

 

you'd need to go to a vendor, find just the center link part, and then get the other little

bits and tabs to make it work.  I think I got mine from Redline back when they had a print catalog-

I picked out the center adjuster, got 2 extra tabs, then filed and modified and extended to get it to work.

 

Couldn't have said it better myself.  Except for our system, nothing out there is designed specifically for the BMW 2002 .  All aftermarket "kits" require mods and adaptation and end up looking like they belong on a 1980s Ford Bronco instead of a BMW.  The end user winds up spending many frustrating hours trying to force those "kits" to work,  Or ends up redoing it to try to make it work like @Stevenc22 above.  Our system eliminates all the guess work, fabrication, and frustration.

Here's a simple graphic that compares some of the possible options.

Oh, and did mention it's shiny!