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Author Topic: Syncing carbs  (Read 2443 times)

Offline Johnj

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Syncing carbs
« on: June 15, 2011, 07:06:44 AM »
I'm ready to sync my carbs and have a few questions. First the screw between #1 and #2 adjusts the #1 carb, right? So the screw between #3 and #4 adjusts #4 to #3, and the screw between #2 and #3 adjusts the set of #3 and #4 to #2. Is this correct? I'm using a homemade manometer (two baby bottles connected with hose,  ½ filled with mineral oil with food coloring suspended in it, which will show difference in pressure).
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Offline tvpierce

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Re: Syncing carbs
« Reply #1 on: June 15, 2011, 07:42:22 AM »
Almost.

The screws are adjusting the throttle plate position of two carbs (or sets of carbs) in relation to each other.

EDIT: I worded that poorly.  I think it's more accurate to say the screws adjust a single plate in relation to another.

So the screw between  1 and 2 adjusts the sync between carbs 1 and 2.  The screw between 3 and 4 adjusts the sync between carbs 3 and 4.  The center screw (between 2 and 3) adjusts the sync between the 1/2 carb bank, and the 3/4 carb bank.
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Offline Strawboss

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Re: Syncing carbs
« Reply #2 on: June 15, 2011, 08:17:56 AM »
Sounds good to me, I never really read up on it, but I start with the middle screw first and go from there, mine are usually so close that after adjusting the middle, I'm usually done. Good luck, its not hard.
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Offline Ranger

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Re: Syncing carbs
« Reply #3 on: June 15, 2011, 02:13:44 PM »
Adjust the left pair first,  (screw between them) and then the right pair (screw between them),  And then sync the two pairs with one hose connected to #1 and one hose connected to #4 (using adjustment screw in the middle of carbs.)    I'm no expert, but that's how I did it, and it worked great. I used RPMs at about 2,200.   
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Offline KenE

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Re: Syncing carbs
« Reply #4 on: June 16, 2011, 01:10:42 AM »
I have a homemade guage- 2 12' pieces of tubing  with 30 weight  oil inside taped to a board, the oil level equal in both loops. One loop connects to 1&2,  the other 3&4.
I balance 1&2, then 3&4, then the pairs. I  sync at the worst buzz rpm... For me 3.8- 4K...
I pull fuel from a small clear aux bottle hung overhead.

KenE
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Offline connie_rider

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Re: Syncing carbs
« Reply #5 on: June 26, 2011, 08:03:54 AM »
Geez, that sounds like a simple "great" idea!
I've never heard it mentioned before and many have asked about syncing carbs and buying/building a system to do the deed.

"Question":   You said you can balance the pairs.

Balancing 1/2 and 3/4 I understand.
But, How do you know the pairs are balanced?
If you do not use exactly the same amount of oil,,, 
would'nt that effect the appearance of the balance between the pairs?

Ride safe, Ted
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