Syncronizing carbs

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pouchy750
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Syncronizing carbs

Post by pouchy750 »

I finally started the engine on my rebuilt 1979 CBX1000 today. It was my first CBX engine, so I was relieved I did the rebuild correctly.
I believe I will have to synchronize the carbs.
From left to right, I believe that #4 is the master carb. I assume that the others have to be balanced in a certain order to each other, what is this sequence?
I can see the carb syncro adjustment screws between carbs #1 & #2, and between carbs #5 & #6, they are at the front of the carbs.
But I can barley see the syncro adjustment screws between carbs #2 & #3, and between carbs #4 & #5, they appear to be buried at the back of the carbs.
How do you get to these rear adjusters, they appear to be blocked by the air vent passage tubes.
Any "how to tech features" advise would be much appreciated.

tevan
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Re: Syncronizing carbs

Post by tevan »

I advise you to get a service manual before you touch them. It explains exactly how to do it and tells you the special screwdriver you need to adjust them..#4 is the one you adjust the others to. Then 5 to 4 then 6 to 4 then 3 to 4 then 2 then 1. Everything from inside out. Motion pro sells the tool to adjust these. I think you can get a PDFs. Manual on this site if you join the club.
:text-welcomewave:

steve murdoch icoa #5322
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Re: Syncronizing carbs

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daves79x
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Re: Syncronizing carbs

Post by daves79x »

If the vent Ts block the adjusters, then you positioned the Ts incorrectly. The scallops in the top frame are for access to the adjusters, not a place to route the Ts. Common mistake. Take the top frames off and rotate the Ts above the frame.

And yes, you will need the special adjusting tool(s) to do a proper sync. Did you bench sync the carbs carefully? If you did that, the bike should run pretty well as is. If you find that the bike won't idle properly, you very well may be going back into the carbs. Not uncommon to have to do that 2 or 3 times until you get them right, if that was your first time doing CBX carbs.

Dave

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spencer
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Re: Syncronizing carbs

Post by spencer »

daves79x wrote:Take the top frames off and rotate the Ts above the frame.
I know you meant to rotate the Ts below the frame.
SCH Rochester, MN

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pouchy750
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Re: Syncronizing carbs

Post by pouchy750 »

Thanks for the link to the Mike Nixon information, it's just what I needed.
It would appear that you need both the long & short adjuster tools.
The previous owner has put goop around the air tees between the 2 sets of carb banks. If this is just for air I don't see why he did that.
I'm hoping I can still reach the rear adjusters.
Again thanks

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Re: Syncronizing carbs

Post by daves79x »

Yes, Spencer, that's what I meant. Still traveling and the memory isn't so great!

Dave

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Re: Syncronizing carbs

Post by patzx12 »

Get Mike Nixon's carb book.
Do you have the carbs off the bike? it not its probably worth pulling them off stripping and cleaning.
I have only ever bench synced my carbs.
I have gauges but haven't used them yet the bike runs fine.

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