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Author Topic: Sync'd carbs, now bike won't idle  (Read 1173 times)

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Offline B.O.X.N.I.F.E.

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Sync'd carbs, now bike won't idle
« on: June 23, 2011, 01:32:12 AM »
Let me say first these carbs were screwed with by someone who's idea of rebuilding was replacing perfectly good jets with keyster kits slathered in LITHIUM GREASE???

I rebuilt them correctly and installed them on the bike. It idled but when I hooked up my carbtune the sync was awful, wildly different vacuum in each carb. A buddy held them at 3k while I sync'd them but now the idler screw won't touch the tab on the linkage.

Is there a mechanical explanation in the linkage the PO may have messed with that I didn't catch? Or is my sync job the likely culprit?
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Offline WarwickE36

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Re: Sync'd carbs, now bike won't idle
« Reply #1 on: June 23, 2011, 06:26:50 AM »
Basically what the last guy said.  You need to make sure you down keep adjusting counterclockwise, if you keep going in that direction you will eventually run out of room. In other words when you finish syncing your master idle screw wont be touching anymore.  Its happened to me before... turn all of the adjusters in a few turns (make sure to do them all equally) and re-sync .. I also dont think 3k is a good place to sync at try 1,500Rpms... once you are close to a good sync idle down to 1k and make sure it will go down this low.
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Offline flybox1

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Re: Sync'd carbs, now bike won't idle
« Reply #2 on: June 23, 2011, 06:57:10 AM »
did you do a bench sync first?
that will get all your slides close, and then only small adjustments are needed during the vac sync to make big changes in vacuum.
once you get your bike idling, do your sync at 1500rpms.
as you make your adjustments, the idle will change, adjust it back to 1500 and continue. repeat.
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Offline fmctm1sw

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Re: Sync'd carbs, now bike won't idle
« Reply #3 on: June 23, 2011, 06:47:14 PM »
Quote from: flybox1 on June 23, 2011, 06:57:10 AM
did you do a bench sync first?

+1.  I always looked through the front and only left a sliver of an opening below the slides on each of them to get started.. 
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Quote from: 754
Dude is that a tire ? or an O-ring..??

Quote from: inkscars
This is not a pod thread
This is not a #$%* on my vacuum gauges thread
This is a help or GTFO thread.

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1973 CB350G
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1973 CB750K3 (http://forums.sohc4.net/index.php?topic=92888.0)
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1994 Honda TRX300
1999 Honda TRX250
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