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I have added a Road Demon 625 cfm vacuum secondary carb to my kids' '65 fb. It was formerly mounted on a 350 Chebby. Now it's on a 289-2v with the factory cam still in place. Also installed are a dual plane intake, tri-Y headers, dual 2-chamber Flowmasters, and a 3.50:1 gear.

The carb is jetted way too rich. It runs OK at idle and part throttle, though not silky smooth. But anything over part throttle and it stumbles and puts out some nasty brown smoke.

So what I need to know is, what size jets would put me in the ball park? Also, to remove a jet do you just stick a screwdriver in the slot and unscrew it, or is there any trick involved?

Yrs, Seven

PS. I already know this carb is larger than ideal for a 289-2v. I'll just confess to my stupidity in advance and get it over with.
 

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Barry Grant's website has the default calibration for their carbs.....I'd reset everything to factory and try it first.....the jetting for your model carb looks a bit rich, but maybe they like somewhat large bleeds in their carbs.
 

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Buy a jet screwdriver from any local parts store or summitracing.com morroso makes a good one. you can use a fat screw driver but be carefull not to damage the jet. I have 65 on my primary and it works pretty good(525 on a mild 302) hey i got a brand new bg jet plate with 60-70 for sale if your intrested :: FREAKIN summit sent me two 60-70 when i wanted one 60-70 and 1 70-80. :(
 

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start at 68 Primary and 73 Secondary and see where that takes you, let me know what that does. I know Demons pretty good. I am about to Buy my 3rd one. So lets see
 

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hey tony i'm thinking of going with a demon carb for my car. which model would you recommend for my stock 302. ::
 

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Sorry TFOB, but I think your jets are fine for 429, but not for 289 with factory cam. I have 600Vac on my 289 and it has 61 primaries and 73 secondaries, but it has two stage power valve that helps to prevent pinging. I would suggest starting at 65 primaries and leaning from there until pinging under heavy load then two sizes back to be on safe side. Then check the secondary side could be somewhere 71, then check the powervalve rating.

Your 625 cfm vacuum unit is not too large. Vacuum secondary carbs are pretty versatile to overcarbing.
 
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