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> Whats wrong with my Carbs?, wants to stall leaving the traffic light.
cgnj
post Mar 29 2017, 10:12 PM
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QUOTE(Hans Jan @ Mar 29 2017, 08:53 PM) *

Thanks for your input.
I'm a little short on time to work on the car.
Instead of learning about timing, I ordered #34 Venturi's (current size is #36). Just because that was something I could do while doing groceries.

Not sure if this is related, but.
The car also comes slow "off its RPM". Meaning when it runs at high RPM and I need to slow down (with foot of the accelerator and clutch pushed in, to downshift), or stop. The engine keeps spinning high for 2 or 3 more seconds.

During up-shifts it sounds like I'm pushing the accelerator between shifts (not the case).

Like I said: Not sure if its related, but worth noting.


I bet you have hex bar linkage. Also webers are single handed. If you look at both of your carbs, you will see the one of them is not on the same end of the shaft as your linkage.

I admit it, I'm a dell fan boy. They have right and left handed castings so this potential problem is avoided. CB sells a mod kit for this.

There are other reasons that dells have the tuning advantage and its not flow out of the box. Thats a misconception because dell came with bigger vent that similar size webers. A clear exaple is a drla 40 came out of the box with 32 or 34 mm vents. The same weber came with 28mm.
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Hans Jan
post Mar 29 2017, 10:26 PM
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QUOTE(cgnj @ Mar 29 2017, 11:12 PM) *

[quote name='Hans Jan' post='2469862' date='Mar 29 2017, 08:53
I bet you have hex bar linkage. Also webers are single handed. If you look at both of your carbs, you will see the one of them is not on the same end of the shaft as your linkage.

I admit it, I'm a dell fan boy. They have right and left handed castings so this potential problem is avoided. CB sells a mod kit for this.

There are other reasons that dells have the tuning advantage and its not flow out of the box. Thats a misconception because dell came with bigger vent that similar size webers. A clear exaple is a drla 40 came out of the box with 32 or 34 mm vents. The same weber came with 28mm.


Indeed it has the Hex-bar linkage. Always imagine that it will be replaced with the Tangerine linkage setup.
Who is CB? And what does this setup look like?
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Hans Jan
post Apr 4 2017, 11:18 AM
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Received the 34mm Venturi's, and i stalled them today.
However; There is no change (car still prevers to die, rather then drive after a full stop).
Also assured that the idle jets are not glogged (not the case).

Eventough most in this community hate the hexbar, I do not think it is to blame in this case. Simply because I cannot get the two carbs to do the same thing with the bar disconnected.

According the EMPI instructions, the idle adjustment screw should only be out a little bit. But to get my car to idle, I have to screw them out very far (almost bottoming out).

When it idles, it is not possible to get the carbs to balance, with the airflow meter. The driverside carb is always flowing more.

The issue with the revs staying up for a prolonged period remains as well.
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Racer Chris
post Apr 4 2017, 12:45 PM
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QUOTE(Hans Jan @ Apr 4 2017, 01:18 PM) *


When it idles, it is not possible to get the carbs to balance, with the airflow meter. The driverside carb is always flowing more.


Use the throttle stop screws to balance between the two carburetors. Ie, screw in the passenger side stop screw to increase flow on that carb.
The idle mixture screws at the base are for matching the two throats on one carb.
Balance the two carbs with the linkage disconnected. Then readjust the drop links.
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Hans Jan
post Apr 4 2017, 02:23 PM
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QUOTE(Racer Chris @ Apr 4 2017, 01:45 PM) *

QUOTE(Hans Jan @ Apr 4 2017, 01:18 PM) *


When it idles, it is not possible to get the carbs to balance, with the airflow meter. The driverside carb is always flowing more.


Use the throttle stop screws to balance between the two carburetors. Ie, screw in the passenger side stop screw to increase flow on that carb.
The idle mixture screws at the base are for matching the two throats on one carb.
Balance the two carbs with the linkage disconnected. Then readjust the drop links.


That is exactly what I'm attempting to do. However the car dies before I get the flow to match left-to-right. The EMPI video says that it causes tuner frustration if these throttle stops are too far out. This is definitely true.

We need someone like you here in Houston.
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Racer Chris
post Apr 4 2017, 03:27 PM
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QUOTE(Hans Jan @ Apr 4 2017, 04:23 PM) *

QUOTE(Racer Chris @ Apr 4 2017, 01:45 PM) *

QUOTE(Hans Jan @ Apr 4 2017, 01:18 PM) *


When it idles, it is not possible to get the carbs to balance, with the airflow meter. The driverside carb is always flowing more.


Use the throttle stop screws to balance between the two carburetors. Ie, screw in the passenger side stop screw to increase flow on that carb.
The idle mixture screws at the base are for matching the two throats on one carb.
Balance the two carbs with the linkage disconnected. Then readjust the drop links.


That is exactly what I'm attempting to do. However the car dies before I get the flow to match left-to-right. The EMPI video says that it causes tuner frustration if these throttle stops are too far out. This is definitely true.

We need someone like you here in Houston.

raise the rpm by turning both stop screws in. Match the flow there before trying to back the rpm down to idle.
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rhodyguy
post Apr 5 2017, 07:19 AM
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Or use 1 idle speed adj screw to raise the idle. The other carb will follow suit and that carb's isac will be off the stop. When you now measure side to side flow you avoid an artificially balanced state that's dependent on the idle speed screws. One goes out of play once it's off the stop and the balanced state is dependent solely on the linkage. If it's out of wack the carbs will be too. If there is a bunch of side to side slop with the cross bar and worn heim joints, you will be struggling. Continuously.
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Hans Jan
post Apr 11 2017, 09:14 PM
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Keeping you up to date:

This weekend I should receive a timing-light in the mail (with an advance dial). At that time I will attempt to check or reset the timing (8 deg at idle and 27 to 34 deg at 3500 rpm). Not yet sure how I'm gonna do this, as I had the fan powder coated last summer, but I should be able to find a way to mark the TDC.

My Uncle (that raced his factory 914-6 in California) mentioned that I should install larger idle jets (0.65mm) to solve the idle problems. His thinking is that my cylinders displace almost 600cc and need more fuel to idle. Does that make sense to ya'll?
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BigFour1973
post Apr 11 2017, 11:19 PM
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I was having similar issues.
-Confirm the intake manifold to head connection is tight and without leaks.
-check if the idle circuit is gunked up. Mine were, so the carb body went in a sonic bath. That seems to have remedied it.
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flyer86d
post Apr 12 2017, 12:05 AM
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I agree with the above post. I had this happen on a customers car. Take the carb off, remove the idle jets and adjustment screws and blast all of the passages out with carb clean with the plastic wand on the spray nozzle. It worked for me. There was gunk in the idle passage in the carb.
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Hans Jan
post Apr 20 2017, 09:59 PM
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Installed larger (0.65mm) idler jets today.
This made a huge difference. I believe that it solves the problem.
As per Racer Chris (and my uncles) advise I have ordered larger main jets (0.170) and air inlets (2.20) to make it complete.

Have been reading a book about Weber carbs, which is really helpful.

Unfortunately I couldn't finish my test drive and dial it in some more, because the ignition switch broke. Have ordered the parts I need from AA (and a starter relay from Amazon).

In the tech-articles is a nice description for how to replace the ignition switch on later models. Is anyone aware of such an article for the 1972 model year?

Br,
Han Jan
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Keith914
post Apr 21 2017, 07:58 AM
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Agree with Forrest.
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Racer Chris
post Apr 21 2017, 08:07 AM
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65 idles will probably make it a bit rich at part throttle, but that's better than too lean.
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Hans Jan
post Apr 28 2017, 05:10 PM
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It's done. With the new jets, the car is running way better.
No more stalling at each stop and smooth transition between idle and driving.
Car runs nicely from below 1,000 up to 5,000 rpm.
At 5,000 rpm the rev-limiter kicks in, like throwing out a boat anchor.

Final jetting:
Venturi:36
Idle: 0.65
Main: 1.70
Air: 2.20

Special thanks to all that have contributed to the solution. You know who you are, and "YOU ROCK".

There is a little back-firing left, at deceleration. But I'm not going to let that keep me from driving and enjoying the ride. Loving every minute, a left hand turn at the neighborhood round-about is just a 495 degree turn for me now. Turns out Im only 12 years old, stuck in this 47year old body.

Consider this tread closed.
Next up: changing ignition switch.

Btw: Once the car looks worthy (might be a while) I will defenitely put the 914world.com sticker on the rear window. Without this community I would have ditched this car long ago.

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