taking carbs off-synching

[ron bayless]

I am going to take my carbs off and check the orings,airbox,boots etc.Will bench synch be necessary or enough?From what i read its a matter of putting like a paper clip under the butterflies and adjusting the nut and screw to get the opening the same on all 4 butterflies.I think some of its surging might stop if I do that.

[Sci85]

A bench sync will get you started but will not take the place of a proper vacuum sync. If you don't have the tools, maybe someone in your area does that can help you out.

I put it off for years because I just didn't want to spend the money but I finally broke down (not enough GS regulars in my area willing to help) and bought the Morgan Tune and it really makes a difference in smoothness of the engine.

Surging is usually caused by a lean condition. If its a light throttle, say 1/8 to 1/4, you could have a vacuum leak at the carb boots or your pilot is too small or improperly adjusted. I would do as you are doing and replace the Orings and boots if old then see if it goes away. Most likely it will.

[FLHGSRay]

That will get you in the ballpark. It still needs to be synced while running. The bench-syncing puts all 4 slides in the same position. It's a starting point. The point of vacuum-syncing is to make all 4 pull the same vacuum, which will likely end up with all 4 slides at a slightly different setting.

[ron bayless]

Thanks.A friend of mine has the synch gauge tool, but he has lots on his plate right now.So I will bench for now.

[Wingsconsin]

Sharing some experience ...

Don't wait too long to get the bike properly vacuum synched..
The bench synch will get the bike running and maybe even running decent...
but the vacuum synch will make all the carbs work together like the system they are designed to be.

On my sons GL1100 Honda Goldwing (4 carbs not inline) we struggled with the synch for some time..but once we had it done we immediately noticed better idling, more power, quieter take offs, and 10% increase in MPG....I am serious and not lying.

The last step of vacuum synch is an important one for proper final performance in my opinion...

[Sandy]

By o-rings, do you mean the the intake boot o-rings or the o-rings in the carbs. If it's just the intake boot o-rings you are checking/replacing and you don't remove the carbs from the rack or disturb any settings on the actual carbs you they should remain in sync. If the intake o-rings were cracked and sucking air then yes you will have resync the carbs. If they look OK (you should still change them anyway because of age) you could probably get away without syncing the carbs again. Of course if they aren't in sync to begin with or it's been quite a while since they were done then you should by all means sync them but simply removing and reinstalling a rack of carbs shouldn't disturb the sync on them.

[ron bayless]

I plan on just replacing the ones on the intake.I have missed the majority of the riding season, so I will wait till it gets cold to disassemble and clean.it gets down to 40 here, about 65 at noon.Still some riding time left. But eventually it will be 3 degrees.