Carb Setting Nightmare, Always better to do it yourself?? Options

[vesnyder]

I have been having issues with adjusting the carbs on my rebuilt 1911 so I thought I would see what a professional could do. This local mechanic specializes in Porsche's and has recently gotten a dyno so I thought I would have him adjust my Webers. The car was running fine but was rich at higher RPM's as confirmed by his dyno and sensors he was using to adjust. I had 28 mm venturis and 115 mains. It ran good but the rich situation gave me concerns particularly on a rebuilt motor. I went to pick it up after he had the car for several days and he said he was having issues. The car was running like crap, backfiring and missing. He said the carbs were adjusted good but it was either the distributor or the valves??? He had put in 195 mains and 34 mm venturis? Upon further inspection he had a 185 in one of the carbs? WTF? On top of that he charged me $320? I am done with so-called experts. This takes the cake!

BTW I am working with Jogn at AirCooled to fix!

[Mark Henry]

my linkage on a 2.6l T4

[r_towle]

my linkage on a 2.6l T4

Nice and pretty.
Got a pic of one in a flat setup?? Not for a beetle??
The cable would not make it there?

I agree that every single one of the linkage setups Sucks...

If the original poster still has issues and cant afford a decent linkage setup, I can offer you this advice.

the CB style cross bar linkage properly setup (as best as you can get it) opens the carbs at different rates.
If you imagine a vertical plane running side to side and you measure the top of the drop link and the bottom on both sides you will notice they are are different angles. Out of the box this is how it sets up.

Start by making sure that side to side you have the drop links parallel...measure from top of one drop link to the top of the other...and bottom to bottom.
Make the parallel first.

Now to fix them so they match in the other direction you need one drop link to mount to the back of the throttle plate and the other to mount to the front.
This varies depending upon what throttle plates you are using..there are quite a few, but non of them fix the problem entirely.

Once you have it close you need to measure what the difference is...so if you are down to 1/2 or 3/4 of an inch you need to move both arms 50% of that difference to make them line up.
Go to the hardware store with the little ball bolt that is mounted to the throttle plate and find one of the little hex rod couplers...its basically a long nut threaded all the way through.
You will also need a tap that matches your ball bolt.
The hex bar couplers are 1/4 20 SAE thread...BUT...you can tap them for the ball cup..it works.
Pick up a few of those, cut them to length, tap them correctly and bolt them onto the throttle plate, then bolt in the ball bolt.

At the end of the day, this is as close as you can get to perfect...you end up being a bit off so you can clear the air cleaner housing, but its alot closer than before.

If you are a picture guy, go to www.356registry.org, look in the technical section and read the article about carb linkage...
This has been an issue since Webers were first bolted on to porsche motors.

Porsche overcame this issue with offset carb manifolds and offet throttle plates on the Solex carbs...really subtle but they step it back just a little bit on both the carbs and the manifold so the end results are the drop links are on the same plane all the way through the cycle.

Rich