do the carbs need to be off to sync them?

[steve_crabb]

i have a 1981 gs550 and i believe i need my carbs sycned, i have to take them off anyways to replace the boots, and was wondering if i could bring them to a shop and have them synced or do they have to be on the bike?
thanks

[chiphead]

Needs to be on the bike with the engine running at idle.

[steve_crabb]

thanks

thanks that

[smithbm]

You should sync them at around 3000 RPM. Search the forums for "carb sync". You'll find everything you need to know.

[Billy Ricks]

If you haven't done, or had, a valve adjustment lately do that before synching. You can bench synch with the carbs off the bike to get them close and that will make vacuum synching go quicker. Just use a thin piece of wire between the bottom of the throttle plate and the carb body to adjust all the plates the same. Number 3 will be your base carb that you adjust with the throttle stop. After that adjust the other three to match with their individual adjusters.

[chef1366]

Thank bwringer for this one.

http://bwringer.com/gs/

[quakeholio]

Syncronizing the carbs is setting the carbs up so that they allow the same amount of fuel mix into the engine. A bench sync will work for getting the bike fired up, but the true work is when the engine is running. Also, if you haven't adjusted the valves, cleaned the carbs, basically give it a full tune up then do the adjustment.

[duaneage]

And the floats need to be checked before that as well.