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Carb pop off pressure

SteveSr

SteveSr

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So I got a o25 here with a carb pop off pressure of around 32 psi. How do I lower it? Clip the spring?
I tried a few different spring, no dif.
pop-off pressure is irrelevant. in fact, you may have damaged the fuel pump diaphragm with 32 PSI. I would check it or replace it. All that you are really looking for is for the carb to hold from 7-10 PSI indefinitely. This is about what the fuel pump puts out and the needle has to hold back.
 

Okie

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pop-off pressure is irrelevant. in fact, you may have damaged the fuel pump diaphragm with 32 PSI. I would check it or replace it. All that you are really looking for is for the carb to hold from 7-10 PSI indefinitely. This is about what the fuel pump puts out and the needle has to hold back.
Right: guys get hung up on POP OFF. that pressure is forcing the inlet needle to stay open.
Slowly put in 5 lbs at first and see if it holds solid at 3-5, if not you have a leaking needle/seat. After repairing go about 7-10 and not any more and it should hold a solid pressure ideally but no leak down less than 3.
It's the holding pressure that you need to test.
 
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