Quadrajet Metering Rods
+ Reply to Thread
Results 1 to 9 of 9

Thread:
Quadrajet Metering Rods

  1. #1
    AAARRRRRGGGGGGG!!!!! Motomatt68's Avatar
    Join Date
    Nov 2009
    Posts
    288

    Default Quadrajet Metering Rods

    I am going to adjust my quadrajet for altitude. I was going to just change the secondary metering rods but was wondering if I should change the primary's also?

    I assume that it is running on the secondarys most of the time but will the primarys have a big effect when the secondarys are open? Do they have to be changed? I dont know why I wouldn't change them besides more work and a little more cash.

    Matt.

  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    Senior Member
    Join Date
    Jul 2008
    Location
    Kingman/Golden Vly, Az
    Posts
    1,278

    Default

    Quote Originally Posted by Motomatt68 View Post
    I am going to adjust my quadrajet for altitude. I was going to just change the secondary metering rods but was wondering if I should change the primary's also?

    I assume that it is running on the secondarys most of the time but will the primarys have a big effect when the secondarys are open? Do they have to be changed? I dont know why I wouldn't change them besides more work and a little more cash.

    Matt.
    do yourself a favor & get rid of the Quadrajet & put either a Edelbrock or Holley on it...much less headaches!!! ...what kind of boat & motor?...whats it used for?...where do you live?

    FastRat

  4. #3
    Senior Member
    Join Date
    Dec 2007
    Location
    Olympia, Washington
    Posts
    588

    Default

    Nothing wrong with a q-jet, put larger jets up front and smaller metering rods in the rear and forget about it. I'm assuming this is a mostly stock application.

  5. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  6. #4
    Senior Member
    Join Date
    Jul 2008
    Location
    Kingman/Golden Vly, Az
    Posts
    1,278

    Default

    Quote Originally Posted by Oldelmn8tr View Post
    Nothing wrong with a q-jet, put larger jets up front and smaller metering rods in the rear and forget about it. I'm assuming this is a mostly stock application.
    i'll bet you dont run a Quadrajet??????

    FastRat

  7. #5
    AAARRRRRGGGGGGG!!!!! Motomatt68's Avatar
    Join Date
    Nov 2009
    Posts
    288

    Default

    I think Q-jets are great. This is the first marine application that I have used but for 4 wheeling they are the next best thing to EFI. I am planning on going with EFI but for now I wanted to get it running better for my vacation.

    The engine is a Volvo 260a (chevy 350) that was set up at about 1200'. It works ok here at 4500' but when I take it to 6000' and above it is a dog. It is hard to pull a skier out of the water.

    Everything is stock. I am also going to get a new engine with more power to go with my EFI but I have not found the right one yet. I am looking for something under $3200. Hopefully under $3000.

    Motorworks has a 406 with 450torque and 405hp for 3200. That would be nice and a hell of a lot more power than I have now.

    I am also considering just putting a cam in the Volvo with EFI and making do for a while.

    Decisions, decisions, decisions.

    Matt.

  8. #6
    Junior Member
    Join Date
    Jul 2010
    Location
    Michigan
    Posts
    7

    Default LEAN the Mixture

    Quote Originally Posted by Oldelmn8tr View Post
    Nothing wrong with a q-jet, put larger jets up front and smaller metering rods in the rear and forget about it. I'm assuming this is a mostly stock application.
    Please re-read what you said. He is going higher in altitude where the air is thinner. That means the carburetor needs smaller primary jets and larger secondary rods to lean out the mixture. The reason it is such a dog is because the mixture is too rich for 6,000 feet.

    In other words he needs to do the opposite of what you suggested.

    Yes, I do run a Q-jet on my boat. I also owned a performance auto clinic and have tuned more carburetors than I can count. If you need help finding jets and rods you can PM me. I still have many sizes left over.

  9. #7
    Senior Member GT Jets's Avatar
    Join Date
    Jun 2008
    Location
    Morgan Hill
    Posts
    2,234

    Default

    How much altitude?

    Quadrajets are great carbs if you don't want to be adjusting on it forever...

    For Tahoe (6200 ft) we normally drop 1 jet size and go up on both metering rods, we also bump the timing about 2 degrees...It runs OK, but definitely not a barnstormer (whatever that means)...
    GT


    Quote Originally Posted by Quickjet View Post
    Put a 300 on the back of it, Flywheel it and a nosecone. $15,000 later you'll have a 65 mph pile of shit......

  10. #8
    Senior Member
    Join Date
    Dec 2007
    Location
    Olympia, Washington
    Posts
    588

    Default

    Sorry about that wette vette, was thinkin bass akwards. You are correct, but I still say the q jet is a great carb.

  11. #9
    AAARRRRRGGGGGGG!!!!! Motomatt68's Avatar
    Join Date
    Nov 2009
    Posts
    288

    Default

    My secondary rods have a CJ stamped on them and my primary rods has something so small that I cant read it. My wife thinks it says 4CE. It looks like that to me but I thought that the primary rods would have a number on them.

    Anyway I need to lean it up for the altitude. What should I use?

    Thanks, Matt.

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Please select your insurance company (Optional)

Log-in


Digg This Thread

Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •  
 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95