Weber question
10-04-18, 03:05 PM
#1
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Weber question
So I’ve ended up purchasing a used Weber 48 DCOE for a really good price got her cleaned up and ready to rock, the question eye have though is I’ve searched the forums to no avail on what the starting jetting should be like, that and I’ve found mixed numbers for the 48 IDAs, I’m running a Stockport 12a with headers and the such, no emissions. The question eye have is would the jetting be about the same for a 48 DCOE as for a 48 IDA, They’re different though of course but would the jetting numbers be approximately the same? And thank you for any help
10-06-18, 10:02 AM
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i'd think the jetting should be really close between the DCOE and the IDA.
for a stock engine, i'd think 50-55 would be about right for an idle jet. the cool thing about the DCOE is that the F number matters (IDA has this in the holder), im not sure what the default is, but you want the next smaller one. (if the default is F9, then you want an F6, see chart (16) Idle Jet for Weber DCOE carburetors)
for an emulsion tube you want an F7, there is a chart for these, goes by cylinder size.
main jet i'm not sure about but i'd start around 180, and go from there. i'd actually see what is in there, and just try it.
for the main airs you start with something that is 50 less than the main jet, and then try richer and leaner until the transition is good.
it is a good idea to change the fuel filter, and i like to test the pump too. i have a container that is supposed to be for juice or something, and its marked every 100cc. the stock pump should do about 600cc in 30 seconds (its in the shop manual), this is more than enough. stock pump also has really steady pressure. so if everything is in spec here you're good, you're just making sure that its working right.
ive tested a bunch of pumps and regulators, and if the stock pump delivers enough fuel it is the best thing. if not i like the mallory pump, as it has a pressure regulator on it that works. the holley regulator is garbage, it kills fuel flow and is bad at regulating pressure. i also don't like the carter fuel pump, it doesn't flow nearly what it should, and doesn't fit the car very well either.
for a stock engine, i'd think 50-55 would be about right for an idle jet. the cool thing about the DCOE is that the F number matters (IDA has this in the holder), im not sure what the default is, but you want the next smaller one. (if the default is F9, then you want an F6, see chart (16) Idle Jet for Weber DCOE carburetors)
for an emulsion tube you want an F7, there is a chart for these, goes by cylinder size.
main jet i'm not sure about but i'd start around 180, and go from there. i'd actually see what is in there, and just try it.
for the main airs you start with something that is 50 less than the main jet, and then try richer and leaner until the transition is good.
it is a good idea to change the fuel filter, and i like to test the pump too. i have a container that is supposed to be for juice or something, and its marked every 100cc. the stock pump should do about 600cc in 30 seconds (its in the shop manual), this is more than enough. stock pump also has really steady pressure. so if everything is in spec here you're good, you're just making sure that its working right.
ive tested a bunch of pumps and regulators, and if the stock pump delivers enough fuel it is the best thing. if not i like the mallory pump, as it has a pressure regulator on it that works. the holley regulator is garbage, it kills fuel flow and is bad at regulating pressure. i also don't like the carter fuel pump, it doesn't flow nearly what it should, and doesn't fit the car very well either.
10-06-18, 12:55 PM
#3
Full Member
Thread Starter
i'd think the jetting should be really close between the DCOE and the IDA.
for a stock engine, i'd think 50-55 would be about right for an idle jet. the cool thing about the DCOE is that the F number matters (IDA has this in the holder), im not sure what the default is, but you want the next smaller one. (if the default is F9, then you want an F6, see chart (16) Idle Jet for Weber DCOE carburetors)
for an emulsion tube you want an F7, there is a chart for these, goes by cylinder size.
main jet i'm not sure about but i'd start around 180, and go from there. i'd actually see what is in there, and just try it.
for the main airs you start with something that is 50 less than the main jet, and then try richer and leaner until the transition is good.
it is a good idea to change the fuel filter, and i like to test the pump too. i have a container that is supposed to be for juice or something, and its marked every 100cc. the stock pump should do about 600cc in 30 seconds (its in the shop manual), this is more than enough. stock pump also has really steady pressure. so if everything is in spec here you're good, you're just making sure that its working right.
ive tested a bunch of pumps and regulators, and if the stock pump delivers enough fuel it is the best thing. if not i like the mallory pump, as it has a pressure regulator on it that works. the holley regulator is garbage, it kills fuel flow and is bad at regulating pressure. i also don't like the carter fuel pump, it doesn't flow nearly what it should, and doesn't fit the car very well either.
for a stock engine, i'd think 50-55 would be about right for an idle jet. the cool thing about the DCOE is that the F number matters (IDA has this in the holder), im not sure what the default is, but you want the next smaller one. (if the default is F9, then you want an F6, see chart (16) Idle Jet for Weber DCOE carburetors)
for an emulsion tube you want an F7, there is a chart for these, goes by cylinder size.
main jet i'm not sure about but i'd start around 180, and go from there. i'd actually see what is in there, and just try it.
for the main airs you start with something that is 50 less than the main jet, and then try richer and leaner until the transition is good.
it is a good idea to change the fuel filter, and i like to test the pump too. i have a container that is supposed to be for juice or something, and its marked every 100cc. the stock pump should do about 600cc in 30 seconds (its in the shop manual), this is more than enough. stock pump also has really steady pressure. so if everything is in spec here you're good, you're just making sure that its working right.
ive tested a bunch of pumps and regulators, and if the stock pump delivers enough fuel it is the best thing. if not i like the mallory pump, as it has a pressure regulator on it that works. the holley regulator is garbage, it kills fuel flow and is bad at regulating pressure. i also don't like the carter fuel pump, it doesn't flow nearly what it should, and doesn't fit the car very well either.
The current jetting it has a 42 mm choke has 210 main 170 air correction emulsion tube is an f11. The carb didn’t come with the idle jets or holders but a good friend of mine has the holders and jets so that ain’t a problem, the stock idle jet on this carb being that it’s a dco sp2 is 65F9 so should eye go for an 65F9? Accel pump is a 45 and the return is closed off
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