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Discussion Starter · #1 ·
I recently split my carbs for a cleaning and a partial rebuild. I've read every thread I could find regarding said subject and haven't found anything regarding my issue. Now that the bike is back together I know that I need to get the carbs re-synced but will that help with me having to partially choke the engine at around 1500rpms in order to keep her running while idling? How many hours labor for a shop to re-sync and adjust the carbs?
 

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Resyncing the carbs on these shouldn't take more than 30 minutes at the most. A shop here once charged me $35 to sync my Goldwing's 4 carbs, but they also left the adjustment screw loose when finished. I now have a Morgan Carbtune that has more than payed for itself.



Maybe someone close will chime in and offer to do it with you.



Did you do a bench sync after you had them coupled back together? If done carefully, you can get very close to a vacuum sync.
 

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I built my own manometer to sync the carbs...if you care to drop by, I'm happy to run through it with you. I have to do mine again soon...still playing with my mixture screws to richen up the burn to a nice golden brown, and that of course throws off the synchronization. Once I get my idle mixtures right I plan to sync em up again.



I had a post several months ago about splitting the carbs, aligning them. it was pretty informative...I'll try to dig it up later as I need to get going.



Carb Link
 

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Discussion Starter · #4 ·
Do the carbs have to be removed to re-sync them? And Rick I really appreciate the offer but I'm not confident that the bike would make it there and back. Your link helped me out with the stalling issue though--I made a simple adjustment to the throttle stop screw. Thanks!
 

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To vacuum sync them, the carbs have to be on the bike and the bike running. You then remove a philips screw in the intake runners and insert a fitting to attach a way to measure vacuum. You would do this on both sides at once.



In between the carbs, but attached to the left carb there is a set screw and a locknut on the linkage connecting the carbs. If not ever messed with, it may have a drop of yellow paint on it. By adjusting this screw. the vacuum can be changed so that both carbs are the same. This allows each cylinder to equally share the load. In theory, this would also be the spot that each carb's butterfly is equally opened.



This all sounds very cut and dried, but in real life, there are compromises. Getting the vacuum exactly the same can be a frustrating challenge. It will want to vary when you tighten the screw, and then not return to equal when you blip the throttle. And tightening the locknut will also change the setting. The adjustment screw also is difficult to access with the engine running and the RPM's also want to change depending on how hard you are pressing down on the screw with your screwdriver. Practice improves your success rate tho. I try to get within 1 mm of Hg if possible, but 2 mm is more doable.
 

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