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Has anyone made or modified an adapter to use the SK carb synchronizer with the 750/101 veloce air plenum. My stock snorkel works fine on the 105 and later plenums.

Thanks,
Jim
 

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I've always had excellent luck synchronizing Webers mechanically rather than via vacuum. Just make sure the butterflies close at the same time with the idle speed screw backed out. Alternatively, you can view down through the transition hole access to see that the butterflies pass the same hole at the same time. Works a charm, do it once, forget about it.
 

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That is my favorite method too. I use to sync them by listening to the carbs through a short piece of hose, but sync'ing them so the butterflies pass the 1st progression holes simultaneously works better for me.
 

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Has anyone made or modified an adapter to use the SK carb synchronizer with the 750/101 veloce air plenum. My stock snorkel works fine on the 105 and later plenums.

Thanks,
Jim
You can use a piece of radiator hose and tape. Worked for me and saved removing the cold air box on my 750.

The other sighting method works best with a thin wire through the progression holes, one on each carb. When they move together, you've got it.

As long as you have the SK, use it.
 

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I would love a picture of the wire throught he progression holes. I'm not sure where the progression holes are.
 

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The progression holes are under a brass screw cap back near the idle mixture adjustment screw. When you remove the screw cap you should see 3 or 4 small holes drilled into the aluminum body of the carburetor. When you move the throttle linkage you should see the throttle plate pass by these holes. The visibility can be helped by shining a small flashlight into the inlet of the carb.
 

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The progression holes are under a brass screw cap back near the idle mixture adjustment screw. When you remove the screw cap you should see 3 or 4 small holes drilled into the aluminum body of the carburetor. When you move the throttle linkage you should see the throttle plate pass by these holes. The visibility can be helped by shining a small flashlight into the inlet of the carb.
FWIW many very new repro Webers (like made in Spain) don't have the screw and have a press fit plug meaning there are no progression holes. The progression holes are about the size of a mechanical pencil lead and are at the bottom of the hole covered by the brass screw
 

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Is this true on the 40DCO3?
 

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The DCO3's don't have the holes.. back to square one. Use the SK. I had driven my DCO3's for years on guess and sound and trying to get an idle and pick up and all the rest by the book . The SK showed me I wasn't even close. They aren't perfect but it performs a lot better. I challenge even rebuilt DCO3's to run perfectly compared to DCOE's with their inherent design flaws. Good luck
 

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DCO3's do have progression holes. See item 28 in the picture. There are brass screw plugs on the underside for viewing, not shown in the picture. You may need mirrors, lights and three hands though.
Doug
Long Beach CA
 

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