engine and drivetrain Installed side drafts, no power WOT.

[mrdew]

I lowered the pressure slightly and it solved the fuel dripping issue for the most part. Attempted to re-tune the system multiple times and absolutly no power still.

[75duce]

The book jetting for the 2000 alpina is the way to go for starters.

A 36 choke will never work good on a 40 dcoe no mater what you do.

32-33-34mm for sure. Its nice to have all 3 for tuning and driving style F16 F9 e tube too, f11 will be hard to tune the cruise and tip in. The idle jet needs to be bigger 55 - 60 especially with the e10 gas we get. The etube idle jet and idle jet mixture screw setting combo will affect good drive ability and cruise the most. The main jet will affect the wot the most.

[TobyB]

A 36 choke will never work good on a 40 dcoe no mater what you do.

heh, I ran them for a couple of years- they metered better than I'd expected.

But a 30 or 32 for a mild street car's better.

I disagree (mildly) about changing the choke for tuning-

you set choke size based on required power (which is in part determined by

the mechanical attributes of the engine)

and then tune the rest of the carb based around the choke.

It varies less than you might think, tho.

t

[75duce]

I ran a 36 choke in a 40 dcoe for a few months too and it will work but

not good . Soggy bottom end and all top end only is what you will get.

No amount of jets or etubes will fix it .

[TobyB]

Yeah, agreed-

there's just not enough vacuum signal below 3k to really let the carb work right.

t

[mrdew]

I ran a compression test:

Cylinder 1: 150

Cylinder 2: 150

Cylinder 3: 150

Cylinder 4: 150

Power balance test:

I pulled ignition wires 1,2,4 and the car runs without change also starts with no issues. Pull ignition wire 3 the car stops. I also removed 1,2,4 wires and turned off the gas to those same cylinders with no change.

I took starter fluid had all the wires attached and sprayed it in individual cylinders.

Cylinder 1: slight increase in RPM with misfire

Cylinder 2: spray all ya want, nothing is going to happen

Cylinder 3: Of course there was an increase it is running on this one

Cylinder 4: Same as cylinder 2

video of running on one cylinder no wires or gas:

I am almost positive it is on the ignition side, but it just is not making sense. I replaced the plugs, and also checked for spark on each wire.

Question: What is the proper gap for these plugs?

[Dave_Ganzer]

+1 for you need a bigger idle jet..... with the idle jet sized correctly the idle mixture screw will be out about 1 to 2 turns for best idle. with your idle jet I would guess you'd need 3+ turns at least....

Do your plug wire check at 15 to 1800 rpm or so, to eliminate a big imbalance issue at idle.

All cylinders should run at that speed. They might not be even, but they all should be running.

What model are your DCOE's?... ie they will say 40DCOExxx on the float bowl.

DaveG

PS The Ireland manifold has a balance tube which makes getting a good idle easier, but you still need to carefully balance each cylinder.

[Dave_Ganzer]

.... what does it do with ALL the wires hooked up?

And be sure you haven't got them mis-wired....

Dave Ganzer

[TobyB]

What's going on is that #3 is doing most of the work.

Not all- it won't run on just 1. So 1, 2 and 4 have to be doing something. Just not their share...

So start troubleshooting #3's bore- and as always, the warm- up circuit

(that comes on when you pull the 'choke' is the first thing to eliminate.

Followed by a bent throttle shaft.

t

[mrdew]

ok, I agree with most of that statement except and I forgot to mention but number four plug was clean like brand new, is not sparking etc.

Also when I spray fuel directly into individual cylinders it only increases RPM in cylinders 1 and 3 but does absolutely nothing in 2 and 4 leading me to believe that the spark is either getting extinguished or no spark is able to be generated in that cylinder because compression is good.

[Dave_Ganzer]

Please verify that you have a means to balance the airflow between cylinders.

BTW your carbs have a small air bypass that is used to even out the 2 cylinders fed by a each carb. You used to have to twist the throttle shaft to fix that....

It is the small screw that sticks out of the barrel at an angle. It has a a lock nut on it. Start out by closing those down completely. Only open one if the carb is not balanced already.

Remove the plug above the transition drillings (just above the mixture screw). You will be able to see the edge of the throttle plate in the lowest hole. Make sure that all 4 throttle plates are in the same position at idle. If they aren't then you need to adjust the throttle linkage until they are. Once you do this it will take very small adjustments to the balance screw (that links the 2 carbs together) to get them to balance perfectly.

AND.... Are you ABSOLUTELY sure that you have the plugs wired correctly? The symptoms you have also fit crossed plug wires. There are combinations that would run just as yours is. Get someone else to check it... We all screw this up once in a while....

Dave Ganzer

[lilcphoto]

Ok so I pulled the jets.

Main Jet: 115

Emulsion tube: f11

air corrector: 200

Choke 36mm

Idle Jet: 45F9

Pump Jet: 40

I've been doing a lot of research today after digging deep into my new DCOE setup and from what I gathered all those numbers (minus the Main Venturi (Choke)) is the factory setup.

Mine came equipped:

Main Venturi (Choke): 36mm

Auxhiliry Venturi: 3.5

Main Jet: 140

Emulsion tube: F15

Air Correction Jet: 160

Idle Jet: 50 F8

Pump Jet: 50

But I haven't ran them and I still have a lot more research to do before I even go any further.

[mrdew]

I agree with you above, I messed up my two numbers for the venturi and the choke, but it appears to be a factory set up. I made a phone call and with the setup I am running I have to rebuild the carbs.