Crappy Carter gas mileage?

[Just 6T9 CHGR]

Took my first long trip on the highway using my newly restored "correct" 4640SA carter carb and got horrible gas mileage with it on the highway.....just a touch over 10mpg!
Averaging about 70mph the whole way.
With my Holley 750 vac secondary carb with the HP main body, I was averaging about 15+ mpg......I think its time to switch back to my Holley....never liked this carb since I put it on either....have a pretty bad off idle stumble that I cant get rid of either....
Anyone else notice this with their Carters?

[A383Wing]

I get great mileage with my Carters...except my black 66 that has a pair of AFB's....I can pull 20mpg with the Daytona....I think maybe there is an issue with yours...maybe float level too high?

[Just 6T9 CHGR]

IDK, this thing is like a $600 paper weight to me now....

[resq302]

Chris,

I guess Scott Smith didn't get it running correctly for ya?  I know mine occasionally has that off idle stumble but Ive just learned to deal with it.  As for the mpg's, I never really looked at mine cause its never really been a big concern.  I didn't buy the car for economy!  

[Just 6T9 CHGR]

Neither do/did I Brian, but when I have something to compare it to it is a concern especially at $4 a gallon!

[resq302]

Wasn't Scott Smith supposed to get it running and tuned perfect on his "mule" engine before they get sent to you?  I remember you had an issue and Scott said that the vacuum advance needed to be hooked up to correct that off idle stumble.  Guess that was not the case huh?

[Just 6T9 CHGR]

nope....

[resq302]

sheesh.  $400 for something that looks nice and pretty and its supposed to run right.       sounds like the job I had with Dick Katter.

[flyinlow]

Is the vacuum advance hooked up and working? Choke coming off properly?

Check the jets, the float levels and the primary metering rod springs are correct.

My experience with Eddy carbs (Carter) is that properly tuned they get a mile or two better millage than the same size Holley.

Gas milage is important. Not just for the cost. Every time you dump more fuel into the engine then it needs, you shorten its life.

[Just 6T9 CHGR]

Vacuum advance is working (had to reinstall it with this carb to even get it to run right)  All other settings are "stock" as per the rebuilder (carb was "run-in" on a test engine before sending it to me)

had the top of it off myself to check these items including the accel pump...all seemed ok

Choke "worked" for the most part...towards the end of last season I just locked it open because I could never get it adjusted/working right because I used the valley tray with the crossover blocked off.  i did drill a few holes in it to get some heat to the choke but definitely not enough.

But alas!   All is right with the world again.   Welcome back old friend!

This carb runs circles around the Carter....even with the HP mainbody & no choke it starts & idles with 2 pumps of the pedal....came back to it after 4 days of putting it on & same thing....2 pumps & vvrrooomm!!


If the Carter sat for more than 1 day I would have to pump/crank the shit out of it to get it to even turn over......

[firefighter3931]

But alas!   All is right with the world again.   Welcome back old friend!

This carb runs circles around the Carter....even with the HP mainbody & no choke it starts & idles with 2 pumps of the pedal....came back to it after 4 days of putting it on & same thing....2 pumps & vvrrooomm!!

No Surprise there....Holley/Proform main body is a nice combination. 


Ron

[Chryco Psycho]

I agree New technology rules !!
I don't waste my time with original carbs

[Charger-Bodie]

Man, I bet you're glad you hadn't sold the Holley and lines.

[Budnicks]

I don't have anything against the Eddy or The Carters but Holleys are much easier to tune to get correct the first time & pull more HP/TQ on any of the dyno tests that I've been involved with just better flow...

[Just 6T9 CHGR]

Man, I bet you're glad you hadn't sold the Holley and lines.

Yup but the Carter IS for sale in the classifieds! 

[Budnicks]

Man, I bet you're glad you hadn't sold the Holley and lines.

Yup but the Carter IS for sale in the classifieds!  

I have a Eddy 750cfm #1411 with electric choke, I can' t hardly give away & it's only been used for cam break in on a engine for a friend of mine, he owed me money & I took the Eddy Carb & Offy 383 aluminum intake in trade, my bad....