carb sync problems.

[odl777]

I was syncing my carbs when i couldnt get 2 of the other carbs to change vacumme, it dont seem to be moving the slide like its supposed to. What do i need to do. thanks

[dcb]

What bike do you have?

[odl777]

79 gs 750, but i think i have figured out the problem. thanks

[PoPr]

What was the problem? I am about to synch a -79 GS myself, but it will be the first time, and no one I know have ever done it before either. So all the help I can get from this forum would be great...

[bwringer]

Yeah, what was it?

Even if it was just a misunderstanding or you feel a little embarrassed about not understanding something, your explanation could be valuable to someone!

[smithbm]

Yeah, what was it?

Even if it was just a misunderstanding or you feel a little embarrassed about not understanding something, your explanation could be valuable to someone!

Like me...

[odl777]

well i thought i turned the nut the locking nut that is enough, but turns out that it could go looser. So i loosended the lock nut and bam seemed to sync just fine.

[KEITH KRAUSE]

well i thought i turned the nut the locking nut that is enough, but turns out that it could go looser. So i loosended the lock nut and bam seemed to sync just fine.

You have to hold the throttle valve adjuster screw still while you loosen the holder nut some. Make your adjustment to the screw, then hold it STILL and torque the holder nut to 3.5 ft/lb (per factory spec). Tightening too much causes binding and can screw up your synch. It also leads to the adjuster screws breaking in half at the head.
After initial vacuum level reads, I always lower any high vacuum level(s) to match the lower ones. This helps avoid back and forth re-adjusting/re-synching so much that the bike will actually run a high idle without even contacting the throttle pulley.