[xodusss]

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GL1100 has, New timing belts, timing perfect. All valves adjusted dead on. New head gaskets and seals. Carbs rebuilt with Randaak kit very carefully. Hooked up a brand new 4 gauge carb sync today and cannot synch carbs. Has a bad knock at idle but will rev to 7000 easily.

Left side carbs 2 and 4 synch just fine about 2/3 of the way down the left side on this gauge. This is not my gauge pic by the way.

Cannot synch them to right side 1 and 4. The non adjustable carburetor #3 shows vacuum way past 2 and 4. All the way past bottom center and into the green. Number 1 carb only shows 1/3 as much vacuum as 2 and 4 and adjusted all the way in. At a complete loss on what to do here. It's like number 3 has way too much vacuum and number 1 has half what it needs.

 

[glhonda]

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I think you'll find #1 throttle plate open too far. #1 is doing all the work, and #3 is just loafing.

Remove the intake runners and do a visual on the plate position on the right side carbs. Just "eyeball" them close to each other and reassemble and do the the sync again.

While you're there, verify you have assembled the screw set correctly that links number 1 and 3 carbs.

 

[xodusss]

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I guess I'm a little confused. When I rebuilt the carbs, I checked the throttle plates and they looked fairly close. Although, if number 1 was doing the work, then it would be the most open and have the most vacuum. Instead, it has no where near the vacuum of the others.. The clincher is, number 3 has no adjustment at all, and way too much vacuum compared to 2 and 4 which look normal. The adjustment screw on 1 does almost nothing in or out. I checked on the side where 3 hooks up to 1, and the y plate is in between the 2 washers under the spring. I'm also getting popping out of 1. I'm wondering if maybe it may be a valve problem.

 

[SuperSkypilot]

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To start with check the compression on all 4 cylinders and the valve lash. Then verify that all 4 chokes are opening all of the way. Then check for vacuum leaks. Finally look at the plugs and verify that all 4 are gaped correctly and that they are all firing. Somewhere in there you will likely find your problem.

By the way if you bench sync he carbs before you install them by using 1/32" drill bits like feeler gauges in between the throttle butterflies and the carb bodies you should have almost perfectly balanced carbs when you hook up the gauges unless you have a problem with one of the above items.
Steve

 

[DaveO430]

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The vacuum on #3 is high because the throttle is closed farther than the rest. Turn the main idle screw in until the reading on #3 drops, the idle speed will likely go pretty high, then adjust the others to it.

 

[Shooter]

imported post

xodusss wrote:

I guess I'm a little confused. When I rebuilt the carbs, I checked the throttle plates and they looked fairly close. Although, if number 1 was doing the work, then it would be the most open and have the most vacuum. Instead, it has no where near the vacuum of the others..

The moreclosed the throttle plate (CV carbs), or the carburator slide(non vacuum carbs), the greater the vacuum... :gunhead: