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4781-6 #2819244
09/10/20 11:12 AM
09/10/20 11:12 AM
Joined: Jan 2003
Posts: 5,991
Anoka County, MN
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Leigh Offline OP
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Leigh  Offline OP
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Anoka County, MN
Anyone have a fixed airbleed main body, they could measure the air bleeds? I just picked up a used one, and want a baseline. I searched extensively, and could only find HP data. Thanks in advance.

Re: 4781-6 [Re: Leigh] #2819276
09/10/20 12:11 PM
09/10/20 12:11 PM
Joined: May 2005
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Apollo, PA.
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In the past I have used Holley's tech line for info like that and they were great.

Re: 4781-6 [Re: B1MAXX] #2819310
09/10/20 01:13 PM
09/10/20 01:13 PM
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Anoka County, MN
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Leigh Offline OP
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Thanks, sounds like a good idea. I noticed the primary and secondary boosters have a different id. I saw the oem secondary jetting, is 2 sizes leaner, so I’ll measure the bleeds, booster discharge channel and od and id, to get an idea why, before calling.

Re: 4781-6 [Re: Leigh] #2819600
09/11/20 08:36 AM
09/11/20 08:36 AM
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Apollo, PA.
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I have a 4781 on the shelf...I'll look and see what -# it is.Just for the heck of it. Let you know what I find.

Re: 4781-6 [Re: B1MAXX] #2819602
09/11/20 08:44 AM
09/11/20 08:44 AM
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Anoka County, MN
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Leigh Offline OP
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If you could measure the primary and secondary pvcr as well, that would be great! Thanks!

Re: 4781-6 [Re: Leigh] #2819654
09/11/20 12:18 PM
09/11/20 12:18 PM
Joined: May 2005
Posts: 1,995
Apollo, PA.
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here is what I have, not sure if it helps you though. It's a 4781-2, the primary bleeds are .070 idle, .026 high speed. The secondary bleeds are .067 idle, .026 high speed. I didn't want to pull a bowl and metering block. its in ready to run shape and didn't want to mess with it but I have written on the bowls primary has a 80 jet with a power valve, and the secondary has a 92 jet with the power valve blocked. I know that doesn't answer the question of the pvcr, but that's the way I have that one set up. up Holley's tech has always been really good.

Re: 4781-6 [Re: B1MAXX] #2819666
09/11/20 12:40 PM
09/11/20 12:40 PM
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Anoka County, MN
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Leigh Offline OP
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Thanks! Did you happen to notice if the primary and secondary boosters are different sizes? That’ll be my last question!

Re: 4781-6 [Re: Leigh] #2820575
09/14/20 12:39 PM
09/14/20 12:39 PM
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Apollo, PA.
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I didn't notice any difference in boosters.

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