Carb Syncing

[Mantis Toboggan]

I plan on running pod filters (K&N or UNI) with the stock air intake (H-pipe?) and was wondering if bench syncing would be enough or do I need to sync on the bike as well? I am running the stock exhaust, if that makes a difference. Can someone also explain to me exactly what syncing does?

 

[Hishman]

Syncing makes the butterflys in the carb open equally. When at idle they should both be just barely open. Syncing has more effect on idle and just off idle. Sync them while running. There are many articles on how on the site

 

[Mantis Toboggan]

Thank you for the explanation! So if it is just done for butterfly operation, then why must it be running? What advantage does using a manometer have over simply bench syncing?

 

[Greasey Fingers]

Even with a manometer its a very touchy business. One little screw one way and it will send one side off. On the bench you would really be just guessing and hoping to get lucky

 

[xschris]

Syncing the carbs will match the vacuum of the engine from the carbs so they pull at the same rate at any rpm. A bench sync can get it running but if they are off even a little the more rpm you go the worse it will get. Always adjust the valves before syncing that way the valves are sealing like they should. Make a manometer and do it right It will be the best thing you can do for tuning a bike.

 

[Mantis Toboggan]

Thanks! I definitely plan on doing so, I just wanted to understand what it was actually doing.