Feelin’ A Little Outta Sync?


Part 2

Article by: Daniel Donley – Pandemonium Custom Choppers – pandemoniumc2.com

Originally Published In The April 2015 Issue Of Cycle Source Magazine

Last month I showed you how to bench synchronize a set of dual carbs for a parallel twin. So for this month’s tech I am going to actually show you how to use a carb synchronization tool. Also show you how close our basic bench synchronization was or wasn’t…


The tool that we are using is a Motion Pro Carburetor synchronization tool. This is a very basic and straightforward tool. I have used it for many years with great results.



Before starting any synchronization process the tool MUST be calibrated. By using this calibration manifold. On a linked set of carburetors the calibration manifold is attached to the non-adjusting carbs intake vacuum port. Typically this is the carburetor that has the idle adjustment.


With the manifold attached to the vacuum intake barb take 2 of the hoses and connect to the synchronization gauge and start the motorcycle and let it idle, you then balance the gauge by turning the balance screws in


or out. After the 2 columns in the synchronization tool are equal with each other the tool is now calibrated.


Remove the calibration manifold and attach one hose to each intake vacuum barb. Start the motorcycle let it idle, all calibrations must be done at operating temperature.


Once I got the engine fired up and to operating temperature this is where the sync gauge was reading. This is how accurate our bench synchronization was. Now, one thing you need to understand is that getting them within one mark of each other on the synchronization tool from setting them on the bench is great. With the tool it allows you to get them even closer!


The bike is running and up to operating temperature. I am going to adjust the balance screw in between the carburetors while watching the synchronization tool to make both columns as equal as possible. This was my result…

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At this point your carburetors are synchronized. Remove the tool and put your vacuum plugs back on your intake ports. I like to secure the vacuum plugs with a small zip tie. Now you can see for yourself that the bench sync will get your carburetors synchronized very closely but the sync tool is the way to go if you want them dead on….. Either way you go its burnouts and wheelies from here on out. But don’t go scaring old ladies…….


So if you have any questions about this month’s tech feel free to give me a call at the shop. 419-576-6812 info@pandemoniumc2.com Daniel Pandemonium Custom Choppers www.pandemoniucustomchoppers. com


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