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Discussion Starter · #1 ·
we have an edelbrock 750 that was running way too rich at idle so we decided to change the metering rods and discovered the rods were broken at the top right before they curve over. they are about 2 years old. i've never heard of this happening before and am looking for any help or ideas on what could have caused this to happen. they were not stuck in it they both were easily removed.
Thanks
 

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aka: kemicalburns
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to much carb there buddy even for a 351w. drop down to a 650 and see your issues go away
 

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Stuck like a MoFo
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sounds like they weren't lined up right with the jets when the top was put back on. Never really heard of them breaking though, if anything i usually brake the bottom part off where it goes into he jet.

Changing those metering rods adjust the whole fuel circuit not just the idle. Did you try playing with the idle mixture screw? Can't remem anymore but does it have anymore mixture adjustment screws on it? It would be your best bet to get a vaccum gauge and tune with the mixture screws and achieve the vaccum signal.

BTW with the metering rod setup only the amount of fuel that the engine wants will be flowing. I don't really see a prob with a 750 and vaccum secondaries. :shrug
 

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Crusher Mike
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kemicalburns said:
to much carb there buddy even for a 351w. drop down to a 650 and see your issues go away

Normally you should only run that with a built motor Heads, Cam, intake. when I stuck that 750 on the vett without the built motor it ran good at Idle but as soon as it was under a lead it would drowned the motor Like kem said 650 or Id even drop it down to a 600.
 

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Stuck like a MoFo
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he is basically changing the CFM by putting in a different set of rods, He should be using a fatter rod and it will lean it right out.

BTW weren't almost all the q-jets of the 70's around 700-750cfm?
 

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85f150 said:
he is basically changing the CFM by putting in a different set of rods, He should be using a fatter rod and it will lean it right out.

BTW weren't almost all the q-jets of the 70's around 700-750cfm?
A 750 won't get a good metering signal on an engine that small at street rpm's. Even leaned down it still won't run optimally. But I digress, that's not what his problem is.
 

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Discussion Starter · #8 ·
sorry i forgot its on a 55 chevy with a 383, its not my mine although i wish it was. i just noticed i didn't include that sorry for the confusion. it has been running on this carb for about 5 years. and he stepped down the metering rods around 2 years ago.

the jets and rods were lined up correctly (well when we removed the broken ones anyway) i had nothing to do with the original istallation so i can't say for certian if they were installed correctly.

according to the manual the rods installed didn't require a jet change but i've been wondering if the rods and jets maybe didn't fit together right and broke although i don't know if that would do it.

thanks for the info i'm no expert on carbs i've only tuned holley's some. usually i'm working on injected engines
 
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