02-15-2024, 11:51 AM | #1 |
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carb jet size
H I I have a 94 carb on a 255 merc stock engine and feel it's running to rich. I'd like to know the proper size jets. I think 54's are in there. Thanks Jim T.
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02-15-2024, 12:35 PM | #2 |
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Re: carb jet size
I found Holley#51 jet size to perform well on my 51 Merc. #54 seems a bit large.
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02-15-2024, 12:45 PM | #3 | |
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Re: carb jet size
Quote:
The main discharge nozzle bars were changed over the years. Three different styles that I can think of. Sal |
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02-15-2024, 04:50 PM | #4 |
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Re: carb jet size
What model 94 do you have?
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02-15-2024, 06:23 PM | #5 |
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Re: carb jet size
flatjack9 It's a 8BA.
Last edited by jimvette59; 02-15-2024 at 06:36 PM. |
02-15-2024, 06:28 PM | #6 |
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Re: carb jet size
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Last edited by jimvette59; 02-15-2024 at 06:38 PM. |
02-15-2024, 07:13 PM | #7 |
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Re: carb jet size
You found it loose?... It has a gasket that must seal properly or you'll run rich. Before you buy a new power valve, remove the old one and test it: It should hold suction to your tongue. The gasket surface should be flat, not a radius as the new ones are. If good, check the gasket and reinstall. If bad, Daytona Parts.com is one source for the correct power valve. I'm not sure which vacuum # to get for an 8BA, someone else should post that value.
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02-15-2024, 09:31 PM | #8 |
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Re: carb jet size
They are generally 7.5
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02-16-2024, 03:03 AM | #9 |
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Re: carb jet size
Where do you find the number?
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02-16-2024, 03:35 AM | #10 |
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Re: carb jet size
Number is stamped on the power valve.
#51 jets came with my 239 cu. in. 8BA Holley 94 2 barrel carb. Worked fine. Changed to a 390 Holley. That also came with #51 jets. Works fine. |
02-16-2024, 12:40 PM | #11 | |
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Re: carb jet size
Quote:
Available through O'Reilly's auto parts and on EBAY. Made in the USA. Also, Dayona carburetor in Florida has good kits and power valves. If the power valve in your carb is wet with fuel on the vacuum side, it's ruptured. Sal |
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02-16-2024, 12:55 PM | #12 | |
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Re: carb jet size
Quote:
https://www.oreillyauto.com/detail/c...it/wlk0/15302b
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02-16-2024, 04:43 PM | #13 |
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Re: carb jet size
Also, I've seen a lot of OLD power valves where the diaphragm is dried up and hard . . . yet still doesn't leak. You should be able to easily actuate the power valve with your finger and with suction. If it doesn't easily move - replace it.
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