Help - what’s wrong with this carb?

[mikeowen17]

Trying to sync and set idle/mix on thr 44IDFs on my new (to me) 2110

Right hand carb behaved like it should - as I took the mix down it got rough, then bought mix back up.

Left carb didn’t react to changes in mix - and when I gave it some throttle there was a ‘flutter’ sound for the first part of the travel before it started to rev.

I’ll attach a video if I can, in which you can hear the ‘flutter’ before the revs pick up.

What’s the issue and how do I fix?


UPDATE: here is a video https://youtube.com/shorts/bawZV99tMq8?feature=share

[67rustavenger]

Sync the carbs with the down rods disconnected. Use a snail sync tool. Once they flow evenly and idle good.
Sync your throttle linkage. You don't want one carbs leading the other when opening the throttle.
One way to check the linkage sync is to, hold one carbs throttle shaft in the idle position. While watching the other carb throttle stop while you try to open the throttles. If it moves. It's out of sync.

Once the above is done and correct, Then go after the mixture screws.

Your engine is gonna run funky with one down rod detached.

Also set your engine timing to at least 10° BTDC. This will help the engine run better at low RPM's. Your idle seems a bit high in the vid.

Someone will be along with their idea on how to get your carbs set correctly in a few minutes.
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[allamaabroad]

Definitely out of sync, left side carb is opening before the right side. Idle is set too high on the left so the progression port is exposed, making it so it’s not running on the idle circuit.

Undo the linkage, sync the carbs with a snail tool, then set your mixture screws. Putting the linkage back together is the last thing you do.

If you’re new to duals, take your time. Your first time syncing and adjusting may take 30+ minutes to do it correctly, it’ll go much quicker with more practice.

Take your time, and do things in the right order
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[FreeBug]

With the linkage completely detached, use a snail to balance and synch. Now put back the linkage, and make sure there is absolutely no binding. Now synch the linkage so that the idles stay put.

Now here comes the final touch, it makes all the difference. This is my technique:

after you balance the idle with the linkage perfectly synched, you use small vise-grips, or something like that...use your imagination..., and block the linkage open ever-so-much, like to keep a constant 1500rpm, with hands off.

Now, at this higher rpm, you use the snail to balance AGAIN, with whatever your linkage has for fine-tuning. Once all 4 are balanced perfectly, free the linkage, and it should fall back to the perfectly synched idle. If it doesn't, something is wrong, generally the linkage's geometry is off.

This is the best technique I have found so far, it really gives perfect balance at all rpm. I later learned it was not only the standard technique at VW for balancing type 3s...they even have a tool for it.

Best of luck.

[vdubrookie]

Cool. Thanks for that tip.