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Dual quad problems?

3rdelke

Well-Known Member
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6:15 AM
Joined
Aug 22, 2015
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Location
missouri
Help, can't seem to get these carbs from leaking, when I turn the fuel pressure down, it won't run below seven pounds. High output mechanical pump
 
What kind of carbs are you running? Don't see why it won't run at 7 psi unless you don't have much volume....
 
Are you running regulator?what mechanical pump? carter ,holley. Fuel bowl float level? Needle /seat
 
Two 750 afb carbs can't remember what. Kinda high pressure mech fuel pump, changed the pressure gauge. Will seven lbs. Pressure cause both carbs to leak ? Think it was
cheap reg, Will change it today.
 
keep pressure in the 6lb range. some regulators don't work well with pulse pumps. a carter 6903 6lb pump may have been a better choice.
 
AFB carbs need no more than 6 psi max. Any higher they will flood. If there is still a problem at 6 psi either the seats are loose in the upper body, there is debris in the needle, or the float height is less than a measured 7/16".
Doug
 
keep pressure in the 6lb range. some regulators don't work well with pulse pumps. a carter 6903 6lb pump may have been a better choice.
Bet that's it, thanks

- - - Updated - - -

Thanks guys
 
yeah, guys. had most of the problems you mentioned. first we had a faulty Chinese regulator, and a bad gauge, changed both out. then found junk under needle and
seat, twice! checking float levels revealed bad floats, after replacing the floats we got it going the best we have to this point, yea! now we just gotta tune this bad boy, (a daunting job) thx, bob and kev
 
All good answers. Also beware of the fuel lines. They can cause no end of aggravation. Gates has new barrier type fuel line that is resistant to ethanol and all of the other chems in new fuel. Also be careful of the fuel fittings. The ones w/ sharp barbs will cut thru the barrier and cause the hose to start deteriorating. Use ones that have rounded barbs, actually more of an upset end than a barb. Of course if you use AN fittings and hose you can bypass all that. When the fuel line starts to deteriorate little pieces will come off and cause problems w/ the needle and seat.
 
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