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914World.com _ 914World Garage _ Carb Downlink Woes
Posted by: Osnabruck914 Jun 21 2024, 11:22 AM
'74 2.0L with Dual Dellorto Carbs
I am sick and tired of jamming myself in the engine compartment with two wrenches to adjust the downlinks when balancing my Dellorto carbs. Are there alternative types of downlinks that are easier to adjust? Picture below. Parts in question are marked with red arrows.
I am fully aware there are better linkage options out there than the CB Performance Hex Bar, but that is what I have and am staying with it for the present time.
Any input appreciated - Osnabruck914
Posted by: 914werke Jun 21 2024, 12:09 PM
why 
Dump that mess & switch to a twist linkage!
Posted by: Superhawk996 Jun 21 2024, 12:19 PM
Might be time to switch back to FI?
On a more helpful note . . .
I have seen these quick disconnect ball linkages. Might consider adding one to an end instead of the heim joint. That might allow you to swing the linkage up and adjust the linkage easier?
The problem is I can’t see this doing anything but adding slop and it would still be a fiddly trial and error job trying to disconnect, adjust, reconnect . . . Rinse lather repeat. 
Posted by: 914werke Jun 21 2024, 12:21 PM
M5-> 10-32 
Posted by: Superhawk996 Jun 21 2024, 12:27 PM
M5-> 10-32
Just for clarity - I agree with you
. Carbs by nature are fiddly to sync and adjust. If that is becoming too much of a burden . . .
Posted by: rhodyguy Jun 21 2024, 12:54 PM
Is the linkage on the rear of the carbs?
Posted by: Osnabruck914 Jun 21 2024, 07:53 PM
Rhodyguy - Yes, the downlink adjusters are at the rear of the carbs. That puts them just under the the front edge of the trunk. Have to actually get my head down inside the compartment to see and manipulate my two wrenches when adjusting. Terrible when the engine is at temperature.
Superhawk - The quick release balls look very interesting. I might experiment. Thanks for the link.
To Others - I have relatively no desire to switch to FI, as these Dellortos run like champs; way better than my experience with Webers.
Osnabruck914
Posted by: Superhawk996 Jun 21 2024, 07:59 PM
Superhawk - The quick release balls look very interesting. I might experiment. Thanks for the link.
As was noted - the link I provided was just a heads up. There are proper 5mm versions out there in addition to those wonky SAE sizes
I’m not sure I’ve ever seen them in both RH and LH threads so I assume you can only do 1 end but maybe with some searching they are out there?
Posted by: ClayPerrine Jun 22 2024, 06:30 AM
A suggestion....
https://tangerineracing.com/shop/ols/products/tangerine-racing-cable-throttle-linkage
Much better than a crossbar link for a 914-4.
Posted by: technicalninja Jun 22 2024, 11:19 AM
Only way to go IMO.
Raby uses a version of this on ALL of his builds that run down drafts.
I've got 4 sets of IDFs and a bunch of linkage.
I'll START with the Tangerine stuff...
Balancing linkage should be a "thing of the past" with that set up.
The OP states he WANTS to stay with the linkage he's got but it's driving him crazy.
Get ready for a LONG drive! 
I've never found a multi carb solid linkage that didn't require monthly adjustment on ANYTHING.
Posted by: Superhawk996 Jun 22 2024, 11:34 AM
So much hate for the infamous cross bar linkage. 
Are they the best? No.
But are they serviceable? Without a doubt. On my original 1.7L I had a el’ cheapo linkage where it was all steel and had a round crossbar to make it even cheaper. Not even a hex bar to ensure lever arms couldn’t rotate on the cross bar. It did have nice shiny chrome and that’s what really matters.
Got me by for about 100k miles over the course of 8 years and I certainly wasn’t adjusting it every month. That would have cut into drinking and chasing girls time when I was in my 20s. 
Just sayin’.
Was my linkage always 100% adjusted and carbs perfectly balanced? Of course not. And. . . Let’s not forget the 911 with carbs have used a cross bar linkage for eons.
They work, and if that’s what the OP has, can afford, or doesn’t want FI, so be it.
Posted by: rhodyguy Jun 23 2024, 08:10 AM
Not all cross bar linkages are created equal. I would suggest putting the linkage on the front of the carbs. At a minimum, you won’t be standing on your head trying to dial them in.
Posted by: burton73 Jun 23 2024, 12:30 PM
I just thought I would point out that Mark Sonners was not 100% happy with his trick cable linkage on his 2170 RAT eng and went to a guy that it considered to be the carb Guru in the Los Angeles area. (Down by the port of LA) his option was it is better to use a hex linkage over the cable and I am showing the difference between the one that Mark just put on and the one shown earlier in this posting. Marks looks cooler and lighter. Not sure that it will work better but it does look tricker (You know a competition toilet flush lever might look cooler but won't flushing any faster) That’s a joke Son
Best Bob B
Posted by: IronHillRestorations Jun 23 2024, 12:49 PM
The CSP center bellcrank is the best budget linkage. The Tangerine cable system is great for most applications.
Posted by: Superhawk996 Jun 23 2024, 01:13 PM
The CSP center bellcrank is the best budget linkage.
And it does move the linkages up higher and more accessible (but still at the rear) than typical crossbar. I’ve seen em’ on the F/S forum every now and then around the neighborhood of $100. Not a bad option for the OP if wanting to stay with carbs but not go all in on a cable system.
Posted by: VaccaRabite Jun 27 2024, 07:16 PM
I’m using the CSP bellcrank for my EFI and I really like it. Veryeasy to adjust.
Zach
Posted by: 914werke Jun 28 2024, 12:31 PM
Posted by: barefoot Jun 29 2024, 07:36 AM
Rhodyguy - Yes, the downlink adjusters are at the rear of the carbs. That puts them just under the the front edge of the trunk. Have to actually get my head down inside the compartment to see and manipulate my two wrenches when adjusting. Terrible when the engine is at temperature.
Superhawk - The quick release balls look very interesting. I might experiment. Thanks for the link.
To Others - I have relatively no desire to switch to FI, as these Dellortos run like champs; way better than my experience with Webers.
Osnabruck914
Switch the linkages to the front side makes adjusting much easier.
Posted by: 930cabman Jun 29 2024, 06:53 PM
I made a bell crank affair a couple years ago, quick/simple/cheap and works great. I will try to get a few pics
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