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Author Topic: Carb Sync Issues - 74 CB550/4  (Read 1640 times)

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grapppa

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Carb Sync Issues - 74 CB550/4
« on: April 03, 2006, 06:45:59 PM »
Well, after consulting with member Dennis today I decided to resync the carbs.  Problem was the idle would not settle down under 2500-3000 rpm after it warmed up.  I sync'd the carbs and I have it settled down.  As I was adjusting the screws I noticed how easily a small adjustment would get out of whack when you tightened down the nut.  ( I think I will custom manufacture (grind down) a 90 degree 8mm wrench to ease the whole process...btw)  How do you keep them tightened down - loctite?
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Offline TwoTired

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Re: Carb Sync Issues - 74 CB550/4
« Reply #1 on: April 03, 2006, 10:40:27 PM »
I also made a tool to adjust the carb sync jam nuts.  I've never used loctite on them, either.  I haven't experienced them vibrating loose.

Cheers,
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Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline Bob Wessner

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Re: Carb Sync Issues - 74 CB550/4
« Reply #2 on: April 04, 2006, 02:34:34 AM »
Quote
As I was adjusting the screws I noticed how easily a small adjustment would get out of whack when you tightened down the nut.

Make sure you are using a screw driver with a blade that fits the slot snuggly when adjusting. If the blade is too thin, the screw can turn slightly as you tighten the lock nut. I've never had any loosen-up either.
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Offline crazypj

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Re: Carb Sync Issues - 74 CB550/4
« Reply #3 on: April 04, 2006, 11:11:38 AM »
you can use a valve adjusting tool or buy a FACOM  No.75 tube wrench and an electrical screwdriver ( parrallel blade, not flared like ''normal' screwdriver.) I found (find?) it better than the valve one. I also have a genuine carb tool but its too long for most applications ( frame gets in the way)
PJ
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I fake being smart pretty good
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grapppa

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Re: Carb Sync Issues - 74 CB550/4
« Reply #4 on: April 09, 2006, 06:07:49 PM »
Well I got them sync'd maybe 85-90% and the bike runs like a charm.  The syncing definitely solved the problem with high idle.  I found that the linkage on the bike creates a lot of variables for the syncing that makes it difficult.  There was a lot of trial and error but persistence paid off.   The final setting of the nut on the screw can throw off the adjustment enough - hence why I couldnt get it to say at 100%.  I guess this is where experience will play a factor.  Good news, the bike is now rideable and reliable enough to take on a nice trip.  Thanks fans ;)
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