high rpm post sync

[Redshirt]

Now that its at least running using all of its cylinders, I took it to a shop to have them sync (I dont own the sync tool yet).
Idles really high (3-3.5k) when hardly warmed up. Enricher gets shut off quickly to avoid higher rev.
Ive searched and found some things folks mention could be the problem.
1.) bad sync. (butterlfy could be holding the others open???)
2.) throttle cable sticking/hanging
3.) carbs running lean (dirty)

the throttle cable was repositioned by mech AFTER sync, stating it would get hung up/pulled while steering. I think it ran high rpm while he was syncing, not sure.

Carbs have been cleaned at least thrice. Rebuild kits installed replacing all the jets, needles, gaskets, the usual kit stuff. Bench sync with bread tie done before taking to shop. They were all set the same so no adjustments made by me prior.

Tank cleaned and coated.

As for a bad sync, I read that one butterfly could be bottoming out, holding the others open. What do I adjust to correct that (if the problem)?
Could the idle be simply set too high? Turn the knob?

Any advice or questions?

[mack]

Idle

Once it's warm enough to not need the enrichment, try turning down the idle. It's not uncommon to to set the sync with a higher than idle rpm to get rid of the bouncing. He may have forgotten to put it back to the 1050-1150 range. I run mine at about 900 to get rid of a lot of the slamming going into first.

[mack]

supplimental

Yes just turn the big knob on the top to adjust idle.
If you didn't remove the butterfly's during cleaning then it's not likely they are hanging. A more likely cause is a vacumn leak at the boots, missing or lose vacum caps on the carb nipples, or when you put the needles back in you may have put the circle clips in the wrong spot. Center is always the best spot to start with.
As for the cable routing, center the bars and twist the throttle then let go. You should here the butterfly's hitting the idle screw. If so then turn the bars fully to the sides repeating each time. If no click then yes its, a routing issue.
Another thing to check is that the vacum hose is routed properly from the vacum advance. It comes into the body of number 2 carb first. The the octy is feed from the vacum nipple on the nuber 2 carb boot. NOT vice versa.

[Redshirt]

Vacuum is correct. Just double checked.
Rough cold starter. Helps if you have gas too. DOH!

[WMarshy]

Just turn down your idle and see how that does. 900-1000 is where I keep mine to reduce the clack from neutral to first... GL

[Redshirt]

ok, turned the idle down to about 1200-1400. It settled into it without reving up when hot, but I need to rebuild my petcock/octy since my parts just arrived. I might tweak it a little more after I get the pets done.

[Bonz]

Hey, about that "clack" going into 1st... something I picked up from another forum...

Pull the clutch in for about 7 seconds before you go into first from a stoplight, etc, assuming you are in neutral. Lets the plates in the clutch "loosen up" for lack of a better term, and then you don't get as much clack.

From my experience it works with my 80 SG.

I'm leery about lowering the idle too much (below approx 1100 rpm or so) because of possible lower oil pressure and low charging output at low rpm. Am I being too conservative on this as it relates to the oil pressure and charging?

Sorry if that gets off subject too much...

[DGXSER]

Personal opinion time....your bike will only be at low idle for a very very minimal amount of time, so as long as it continues to run, and your turn signals continue to flash and such, your not hurting it at lower idle. The oil pressure difference is probably about nil at the 900 versus 1100 rpms, when you consider the engine is set up for 8500 rpm redline.

[Bonz]

Factory specs in the service manual call for a 950-1050 rpm idle, so 900 isn't so far off. With that said, my headlight gets dim and the headlight warning light begins to glow when idle goes much under 1000 rpm (according to the bikes tach, not necessarily as accurate as a separate reading that you could get from an external tach). Don't need a dim headlight sitting at a stop in the evening.

I'll just pull my clutch in a few seconds before I shift into first from a stop to minimize the dreaded clunk, enjoy a higher oil pressure and call it good with an idle speed around 1100 rpm.