They'll never work, I'll give ya $100 for 'em just to help you out.
Before you ever bolt them to a engine you need to give them the once over. Check the throttle shafts for play, if they are loose they need rebushed. Hold them up and look down each barrel toward a light, you should only be able to see the slightest bit of light around the butterflies. If you see a bunch of light open the butterflies and look at their edges, they should be square. If they are sharp they need to be replaced, Redline Weber stocks them. I have seen them that were worn so much that they were like razor blades. This is a big air leak, just like the shaft bushing. Next, look at the air bypass screw in the barrels. These are easily over tightened which will bust out the seat and, you guessed it, a BIG air leak. Any of the things that I have described will cause the engine to idle very high and keep you from adjusting it down where it needs to be. It will also throw your idle jetting off giving you stumbles that are near impossible to get rid of.
Hope this helps.....
