No vacuum during carb sync?

[Slick]

I recently installed new boots (Air>Carb) because the old ones were torn. Yesterday, I attempted to sync the carbs. Although at first, everything was normal, I seem to have lost vacuum at some point. The rods on my "CarbTune Pro" stopped bouncing at idle. I could get them to move though; if I rev the engine, the rods would jump up as the engine was reving down. I checked for malfunction on the tool and everything looks to be working fine. Is there something I could be missing?


Side Note:
I synced my carbs last year with this tool, without a problem.

[Pat Conlon]

Are you laying the Carb Tune flat? I did that and got wrong readings.
Hang the Carb Tune by it's hoses off your handgrip so the position is vertical. The rods move up and down much better that way.

[racerman_27410]

make sure you still have the restrictors in the tubing to the carb joints




KOokaloo!


Frank

[Mark Olson]

you may need to adjust your valves.

[craigo]

Just a thought, but has anyone messed with the little screws on the top of the carbs?  These are the air mixture screws??? Mine were buggered and couldn't get the carbs to sync until I reset them.

CraigO

[Slick]

Yes it is standing straight up, Yes the restrictors are still in place. Please remember that the gauges were working fine for a bit BEFORE i lost vacuum.

I have since tore the carbs apart and found a lot of gunk inside. Maybe this was part of my problem. I will report back with results when I get a chance to put them back on.

[Steve_in_Florida]

How long did the carbs sit with old fuel in them? (...and DON'T lie!)

Today's gas wreaks havoc with carbs if it evaporates in them. Coats the insides with varnish.

Ever smell 20-year old gas?



It's a smell that you CANNOT get rid of!

[Slick]

How long did the carbs sit with old fuel in them? (...and DON'T lie!)

Today's gas wreaks havoc with carbs if it evaporates in them. Coats the insides with varnish.

Ever smell 20-year old gas?



It's a smell that you CANNOT get rid of!

Gas was about 4 months old (I know I know). I did drain the bowls before starting, yet I would love to know how the bike was running so well with the carbs looking the way they did.

[SlowOldGuy]

Was the choke on when you were trying to sync?

DavidR.

[Slick]

Was the choke on when you were trying to sync?

DavidR.

I choked to start the bike cold, waited for it to warm up, turned it off, hooked up sync tool, then started bike again w/o choke to sync.

[Dan Filetti]

The Carb Tune itself has not sprung a vacuum leak -has it?  Can you lift a rod by a applying vacuum from another source?

Dan

[FJmonkey]

Pull off one hose at a time and see how the engine runs. You have to have vacuum, the carbs won't work without it.

[Dan Filetti]

The Carb Tune itself has not sprung a vacuum leak -has it?  Can you lift a rod by a applying vacuum from another source?

Dan

[Notice I DID NOT say: 'lift a rod by sucking on a tube"]...

[Slick]

The Carb Tune itself has not sprung a vacuum leak -has it?  Can you lift a rod by a applying vacuum from another source?

Dan

[Notice I DID NOT say: 'lift a rod by sucking on a tube"]...

Why not?

[Pat Conlon]

Reminds me, where the hell is Klavdy?

I misread the OP, is there no vacuum reading on any cylinders?