Recently there has been a lot of discussion about statically synching the carbs after a rebuild.

 Here is my way. It doesn't involve any paperclips, torches, guessing at openings, etc.

It's simple and gets the synch very close; I've had several messages saying that they run close enough that gauge synching can be left to a more convenient time.

If these are a set that you have overhauled, I'm going to assume that you have checked that all the parts are good. No worn out link bushes (on 76 on, fix for the early sprung ones later)), no loose arm pins on the quadrant (that does happen), all the throttles move freely and the notoriously 'prone to jamming' adjuster on #4 is free to move. More info on that here.

 

On the 1000/1100:

Carb#3 is the control carb. All other carbs are adjusted to it.

Set up the actuating quadrant without the spring being in tension.

Back off all the adjusters and the idle screw on the quadrant.

Hold the throttle plate of #3 firmly closed with a finger, then push the plate of #1 closed. You will see movement at the adjuster. Unscrew the adjuster in increments until it no longer moves under the finger pressure on #1. Double check that the two plates are shut at exactly the same time. Take your time and make the tiniest of adjustments to ensure this.

Now repeat this for the adjuster between #4 and #2 by holding #4 shut.

Finally, hold the plate of #3 and adjust #4 in the same manner. On the early 1000 sprung arms this is more difficult.

You have to make sure that the pins are not moving in the arms when you do this. Best to do the fix on the arm springs first.

See Here.

Fit the quadrant spring.

Move the actuating arms so that you can hear the throttle plates shutting (not SLAMMING shut!)

They should all sound the same. In other words, you should not hear one plate shut before the others. If you do, go back and check.

With that done, turn the idle adjuster screw so that the throttle plates are just opening.

Refit the carbs.

 

GL1200:

Note that the GL1200 has the #4 carb as the control carb and the quadrant has to come off the release the spring behind it and again to refit it.