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Old 10-06-2008, 08:27 PM
BIGS BIGS is offline
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Hey Guys...like rustydawg said, a 50CC pump kit purcase can allot of times be a cover up for some other carb/ignition problems and on most carbs a 30CC pump is enough.......But in the case of a 850 Holley, they have the largest venturi and butterfly diameter in the whole family of 4150 style carbs....at the top of each venturi it measures 1.600 and the butterflys measure 1.750...that leaves hardly no taper in the venturis and the air speed down low is real bad......causing allot of "transfer" style issues.....and a large "hole" of instantly opened up CFM introduced to the engine, hence making it nessesary for the bigger 50CC pumps to help cover up the flat spot.....If your engine is realitivly healthy then you should keep the 50CC pumps on there becasue you will probably need them.......Later, Jesse @ BIGS!!
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