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Author Topic: Vacuum gauge woos  (Read 1312 times)

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Offline jchabino

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Vacuum gauge woos
« on: June 29, 2015, 10:44:36 AM »
Hello all,
First of all thanks to you all in helping me restoring my 76 550. I am synching the carbs and do not understand how to convert cmHG to vacuum inches on my gauges. 
I have a set of 4 gauges that I bought off the net.  I see pics of a lot of guys using them.   The set is mounted on a blue plate with the words "carburetor sychronizer" along the top of the plate.  The 550 carbs are supposed to be set between 16-23 cm Hg. There are no cmHg markings on my gauges only "vacuum inches".  My question is how do I convert cmHg to vacuum imches so I can set these up correctly.  It seems to run pretty good when I set to 9 vacuum inches at idle. Thanks in advance for you help
Regards, Jerry
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Offline flybox1

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Re: Vacuum gauge woos
« Reply #1 on: June 29, 2015, 10:49:29 AM »
Specific value does not matter.  Equality between all four does...
Get them all the same.  Its all you need to do.
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Offline Deltarider

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Re: Vacuum gauge woos
« Reply #2 on: June 29, 2015, 10:52:26 AM »
Quote
Specific value does not matter.  Equality between all four does...
Get them all the same.  Its all you need to do.
Specific values are indeed irrelevant. That's why some choose to build their own synchronizer. Concentrate on equal pull.
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Offline 70CB750

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Re: Vacuum gauge woos
« Reply #3 on: June 29, 2015, 10:53:04 AM »
Same vacuum accross is all you need, values are not important.
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Offline Deltarider

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Re: Vacuum gauge woos
« Reply #4 on: June 29, 2015, 10:57:13 AM »
Quote
Values are not important.
Well, certain values are ofcourse.  ;D
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Offline calj737

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Re: Vacuum gauge woos
« Reply #5 on: June 29, 2015, 11:17:19 AM »
Quote from: Deltarider on June 29, 2015, 10:57:13 AM
Quote
Values are not important.
Well, certain values are ofcourse.  :'(
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Deltarider

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Re: Vacuum gauge woos
« Reply #6 on: June 29, 2015, 11:26:15 AM »
Calj737, I would appeciate if you would stop your habit of 'fixing' my contributions. It could easily cause confusion and it reminds me of practices in the novel '1984'. Maybe you've heard of that novel and I don't like those practices. I am quite capable of expressing myself. Thank you very much.
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Offline calj737

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Re: Vacuum gauge woos
« Reply #7 on: June 29, 2015, 11:44:58 AM »
 ;D ;D ;D it wasn't a "fix" it was an alteration. It was faster to respond that way. Express yourself all day long, Delta. I enjoy First Amendment Liberty from everyone.

Edit: was laughing so hard I hit the post button before I could finish.
« Last Edit: June 29, 2015, 11:47:38 AM by calj737 »
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'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Roach Carver

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Re: Vacuum gauge woos
« Reply #8 on: June 29, 2015, 12:10:39 PM »
Now I'm laughing too. I like the quotes.
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Offline BobbyR

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Re: Vacuum gauge woos
« Reply #9 on: June 29, 2015, 01:40:39 PM »
The bottom line jchabino is that what you want is even vacuum across all four carbs at idle.

The other bottom line is the guys like to #$%* around and that is OK. Guys who ride bikes are usually not delicate.
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Offline jchabino

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Re: Vacuum gauge woos
« Reply #10 on: June 29, 2015, 04:28:46 PM »
Thanks guys.  I appreciate it
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Offline BobbyR

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Re: Vacuum gauge woos
« Reply #11 on: June 29, 2015, 05:34:09 PM »
Oh yeah one last thing. It is best if you remove the plastic cover over the gunge and play each one into the same carb. They should all read the same, if they do not there is a brass colored screw which you can used as an adjustment to calibrate them.

When you do the job it is best to place a window fan in front of the motor to help keep it from overheating. 
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Dedicated to Sgt. Howard Bruckner 1950 - 1969. KIA LONG KHANH.

But we were boys, and boys will be boys, and so they will. To us, everything was dangerous, but what of that? Had we not been made to live forever?
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