79 550 Carb Sync

[Rob32401]

I’m running into an issue trying to sync my carbs. Noticed one of my slides when adjusted properly in the closed throttle position won’t tighten with the lock nut. To get the lock but to tightening I would have to tighten the adjuster screw past when the slide stops moving and it would push up on the throttle shaft and raise all the other slides. I shimmed this one with a other washer so the lock nut would tighten in the correct position. After adjusting setting this one in the correct position, I should note it was the number 3 carb as recommended to set first, the number 2 carb has no adjustment now. Either direction I turn the screw the slide does not adjust. I don’t see any issues with the slide linkage. I had replaced one of the slides because the previous owner had somehow managed to bend the link. There’s evidence these have been apart. Is this normal, or am I missing something? Is there anyone that I could ship these too so they can repair and adjust them? I’ve been slowly working on this bike for over a year, and time to work on it is slim. Thanks for any help anyone can give!

[Nessism]

The baseline setting for the slide adjustment is messed up. All the adjusters should first be set to the middle of the range within the slide, then start syncing from there.

[Rob32401]

Ah, I was unaware there was another adjustment in the slides. I will set those and go back. Thank you very much! Didn’t want to buy a new set, the bike only has 8k on it.

[phydeauxmutt]

I should note it was the number 3 carb as recommended to set first, ...

The recommendation to set Blogs first is only for the BS series carbs, which came out on the '80 models of the four-cylinder GSes.

[Rob32401]

The sheet I’m following is from the bike cliff website on how to rebuild and set these carbs. I didn’t see any reason why the 3rd should be set first, but didn’t want to deviate from those instructions. They seem to be very thorough, and are about the only resource I can find for this years carbs.

[Nessism]

The sheet I’m following is from the bike cliff website on how to rebuild and set these carbs. I didn’t see any reason why the 3rd should be set first, but didn’t want to deviate from those instructions. They seem to be very thorough, and are about the only resource I can find for this years carbs.

The 3rd carb doesn't need to be first, they all just need to be the same. I wasn't joking about making sure the adjusters are in the middle of their range too. If you don't do this the adjuster for one of the carbs may bottom, or top, out, and when that happens you can't get a proper sync.

[Rob32401]

Hoping to have time tomorrow to have another look at them. I planned to follow your advice. I’m very thankful for your assistance.