Symptoms of carbs out of sync?

What would be the symptoms of carbs that were out of sync?

I keep hearing about carb sync and I have no idea how the bike would run if they weren't in sync.

Still learning. Thanks!

 

High idle that's difficult to adjust down to normal. (This could also be maladjusted throttle cable.)

Very slow return to idle when revved.

Generally poor engine running.

More?

Z

 

Rev's "Hunting" for a steady spot. Not able to stay leveled-out at Idle.

Exhaust note uneven and puh-puh-popping.

Rummmmmmmmmmmmmmm-puh-puh-rummmmmmmmmm.
-or-
Rummmmm-puh-puh ... puh-PUH ... PUH-pa rummmmmmmmm.

 

My 550 had the high idle that was hard to adjust; this after cleaning carbs and new intake boots.

First try at synching them left me with a bike that wouldn't start or run (I was a bit ham-fisted turning the screws), so I took off the carbs, bench synched and was back where I started: its starts right up and runs like a charm, but idles at 3500-4000 rpm.

I've turned the idle screw and checked throttle cable free play, to no effect. BUT, if I'm at a light and start using the clutch to bring the idle down, it sometimes will revert to an idle at around 1500 rpm. What gives? I figure if they're out ot synch, they're out of synch, so why does it sometimes want to idle more normally?

My slides are clunking, the mixture screws are three turns out, I know my throttle shaft seals need replacing but could that push the idle that high? I'm going to try synching again this weekend, but I'm wondering if I'm still going to have this problem.

 

Eliminate the obvious first.

Handlebar adjustment of cable slack ... too tight. Undo the locking collar and back-off the cable.

Problem with the way the cable is routed. Binding?

Possible broken strand within sheath ... snagging.

Wrong cable. Too short?
. . . . . . . . . . . . . . . . . . . . . . . . . . .

Undo the cable and tune-up the low-end without the rack being hooked-up to the throttle cable.

Back-out the Idle and start the process closed.
Tweak the Idle Adjustment until it will keep running.
If the Idle is running-away on you without the Idle Adjustment touching ... look for air leaks.
If there's NO air leaks ... Tweak the Mixture Screws Closed until the engine starts to run rough ... then, Out again until the Idle smooths-out.

 

I have the same problem on two of my 550's. I discovered that if I push down on the right hand screw on the carbs then I can get the idle to go down to a steady 1500. Having recently adjusted the pilot screws I am sure that I also have the both bikes running a little too rich. After spraying carbs with wd40 on the springs I found that the springs were sticking, things seemed to get better. lubricate the springs and shafts first and see what results you get.