Carb sync tool

[Pols497]

I just bought one of the Swiss carb sync tools and I am in the process of kitting the carbs. Does anyone know how to sync the carbs. There were no instructions with the tool when I opened it up. Where do you place the tool? It has some holes under the rubber connecter that you can see if you rotate it. Any advice would greatly be appreciated.

[JC]

This is how I do it and if there is anybody to correct me then please do. I warm the vehicle first, then I remove the carb air intake cover. The tool should now fit in one of the carbs. Start the Pinz and lock it running just above idle with the throttle lock. (I do this so I sync the running carbs and not the idle carbs). You are trying for the same number reading on the tool for each of the carbs, moving the tool back and forth as adjusting, and it is adjusted with the linkages. After you get them synced then lower the Pinz back to Idle and sync with the idle screws, and the recommended idle speed it is in the manual. 800rpm I think.

This is like the tool I have mine is the BK model and not the SK

[Pols497]

Mine must be the SK model. I am wondering about the holes that you can expose if you rotate the rubber boot. Expose them or not?

[kpoling]

I too will be tackling this task soon. I have a Twinmax synchronizer I use for motorcycles that you connect to a vacuum line off of the carb or throttle body, it works very well. Are there vacuum ports on the carbs or do you need a unit like the pictures above?

Twinmax:
http://picasaweb.google.com/lh/photo/sL ... directlink

[pinzinator]

The instructions for the Twinmax say to block any lines between the carbs. Under the tin on a Pinz engine is a balance line between manifolds, so I assume this would have to be blocked in order to get correct readings.
Where would the Twinmax be connected to the Zenith carbs on the Pinzgauer?

[Jim LaGuardia]

If you are rebuilding the carbs you will sync them twice.
First get fuel into the fresh carbs and start the engine. Next put the sync tool on the front carb and read the value(should be between 6-10kph) now with the link off of the rear carb adjust till it matches the front carb value.
Now let the engine warm up, adjust the idle screws and then re-check your adjustments, and re attach the link to the rear carb.
Double check your work and go drive

[kpoling]

Pinzinator: If there is a balance line between the carbs, I will remove it & connect to each of the ports separately. I am assuming it is a rubber tube? I only peeked under the lid, I have not removed the whole cover in a while and did not see the balance tube.

Pols: Does you sync tool look like the one in JC's attached picture?

Regards, Kevin

[Jim LaGuardia]

Do not disconnect and block the EQUALIZER port .
My instructions are correct for the tool pictured.
There are no vac port taps on Zenith carbs, use the correct tool as pictured

[Pols497]

Kevin, the carb sync tool I have looks like that except on the bottom part that you set down on top of the carb. I bought it from Swiss Army in Fayetteville , Ark.

[lindenengineering]

Guys
You might want to try this method.
1)make sure the Ign timing is correct.

2) Since the front carb is operated by the upper throttle link disconnect it by prying off the upper joint with a flat screwdriver.
The carburetors can now be operated independently.

3) Set the slow running mixture jets to 1.25 to 1.5 turns out (externals) 2 turns out tamper proof internal styles.

4) With the engine off floor the gas pedal and make sure the rear carburetor is going flat out--don't worry about the front one at this stage.

5) Fire the engine and adjust the REAR carburetor to 9.75 on the balancer

6) Without touching the front throttle rod adjust the front carburetor to run at the same depression flow 9.75.with the balancer on the front carb

The engine should now be running very smoothly at about 850r/m.

7) Now offer the detached front throttle rod to the front carburetor arm, you may have to adjust it up or down to slip onto the ball joint without lifting the front carb off of idle or the rear.
With the balancer on the rear carb watch the needle--If it rises the front throttle the rod is too short--if the front carb lifts off of idle the rod is too long. Adjust to get both rods on without disturbibg the idle.

Once completed gently lift the throttle by foot or hand to raise the revs to 1500 or so and then take another reading, both carbs should be showing the SAME flow for balance. Investigate if you have a wide tolerance between the two readings. Now shut the engine down and try the carbs at flat out by flooring the pedal.

9) Now check for mixture air fuel ratio. I use a gas analyzer to get the mixture into E compliance at that stage. You will probably have to guess it by tweeking the mixture scews.
CAUTION.
If your Pinz is a "spit back" type due to timing/carb problems those balancers DO NOT like instant reverse blasts of mixture and it WILL wreck your expensive tester--Never hold the unit firmly upon the throat rather just let it sit there--I have had them blown off into the engine compartment and I am on my 5th unit in the ten years. of doing this so beware!

If you have gas analyzer expect to see about 2.00%CO and 225 PPM HC's for nice well run low wear engine. If the unit shows wear 3.5 to 3.75% CO and 425ppm HC's is often commonplace.
Happy tuning & Merry Christmas
Dennis

[djw]

Guys
You might want to try this method.
1)make sure the Ign timing is correct.

2) Since the front carb is operated by the upper throttle link disconnect it by prying off the upper joint with a flat screwdriver.
The carburetors can now be operated independently.

3) Set the slow running mixture jets to 1.25 to 1.5 turns out (externals) 2 turns out tamper proof internal styles.

4) With the engine off floor the gas pedal and make sure the rear carburetor is going flat out--don't worry about the front one at this stage.

5) Fire the engine and adjust the REAR carburetor to 9.75 on the balancer

6) Without touching the front throttle rod adjust the front carburetor to run at the same depression flow 9.75.with the balancer on the front carb

The engine should now be running very smoothly at about 850r/m.

7) Now offer the detached front throttle rod to the front carburetor arm, you may have to adjust it up or down to slip onto the ball joint without lifting the front carb off of idle or the rear.
With the balancer on the rear carb watch the needle--If it rises the front throttle the rod is too short--if the front carb lifts off of idle the rod is too long. Adjust to get both rods on without disturbibg the idle.

Once completed gently lift the throttle by foot or hand to raise the revs to 1500 or so and then take another reading, both carbs should be showing the SAME flow for balance. Investigate if you have a wide tolerance between the two readings. Now shut the engine down and try the carbs at flat out by flooring the pedal.

9) Now check for mixture air fuel ratio. I use a gas analyzer to get the mixture into E compliance at that stage. You will probably have to guess it by tweeking the mixture scews.
CAUTION.
If your Pinz is a "spit back" type due to timing/carb problems those balancers DO NOT like instant reverse blasts of mixture and it WILL wreck your expensive tester--Never hold the unit firmly upon the throat rather just let it sit there--I have had them blown off into the engine compartment and I am on my 5th unit in the ten years. of doing this so beware!

If you have gas analyzer expect to see about 2.00%CO and 225 PPM HC's for nice well run low wear engine. If the unit shows wear 3.5 to 3.75% CO and 425ppm HC's is often commonplace.
Happy tuning & Merry Christmas
Dennis

At the risk of a spanking for resurrecting an old thread, this post is the best I have seen on carb sync. Mine were way out, now they are in perfect sync.

I might also add what a huge difference syncing the carbs has made in off-idle throttle response and drivability, idling, and stability of the choke operation (idle no longer hunts when cold and on choke). I should have known they were pretty far out based on these symptoms but these things take time.

Thank you Dennis.