1. Registration trouble? Please use the "Contact Us" link at the bottom right corner of the page and your issue will be resolved.
    Dismiss Notice

Is it necessary.....

Discussion in 'Early CJ5 and CJ6 Tech' started by Get Dirty, Apr 27, 2007.

  1. Apr 27, 2007
    Get Dirty

    Get Dirty New Member

    Telluride, CO
    Joined:
    Aug 25, 2005
    Messages:
    22
    I have a stock Rochester 2G Carb on my dauntless with the original jets in it. I think they are .051. The jeep is now lives at 9000ft instead of 200ft above sea level. (it ran perfect at 200ft before it got here) It is definetly running sluggish especially up hill. I have had the timing adjusted and the carb tuned in but it still boggs and almost stalls on hills especially in the dirt. I am thinking that it may be the float, and my mechanic said this carb should not need different jets, but I am starting to think he is wrong on that.

    What do you all think should I change the jets or should I be able to adjust it until it is running right.
     
  2. Apr 27, 2007
    Rondog

    Rondog just hangin' out

    Parker, CO
    Joined:
    Aug 25, 2005
    Messages:
    2,918
    Logic tells me that it would be running far richer at 9000ft. asl than at 200ft. asl, so I'd assume that I'd need to change the jets. But that's JMHO.

    I know when I rode my old '75 Harley from Oklahoma to Colorado, its performance was severely affected. I didn't think it would make it to the top of Pike's Peak, we'd stop to rest and it actually had raw gas running out of the mufflers.
     
  3. Apr 27, 2007
    MOP

    MOP Active Member

    Pullman, WA
    Joined:
    Sep 25, 2003
    Messages:
    1,131
    I think several CO and NM folks are running .047 or .048's?
     
  4. Apr 28, 2007
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
    Joined:
    Jul 30, 2003
    Messages:
    8,513
    on my Colorado vacation last year
    I installed the .047 jets and advanced the timing 3-4 degrees
    it does make a difference
    I also have an inline fuel pressure regulator and for running the rocky passes I turn it down to 2 psi to help with float bounce/flooding
    it ran like a top
    even with those mods, the altitude still affects performance/giddy-up go
    for you at the least, I'd change the jets and bump the timing up slightly
    ymmv
     
  5. Apr 28, 2007
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
    Joined:
    Jul 30, 2003
    Messages:
    8,513
  6. Apr 28, 2007
    Get Dirty

    Get Dirty New Member

    Telluride, CO
    Joined:
    Aug 25, 2005
    Messages:
    22
    So I live at 9500', but as soon as I hit the trail I am heading up to 12,000 and above. I normally drive around town (9500') and hit the trails on the weekends with the kids. I am wondering if I should install a .049 which seems to be rated for above 5000' or should I put in the .047 which is rated for above 10,000'. I dont want to have to change the jets every weekend so I would like to settle on one or the other. I do go down to the 5000ish' elevation every once in a while and a lot of the back country around here is in the 7000' range as well. What would you do?
     
  7. Apr 28, 2007
    MOP

    MOP Active Member

    Pullman, WA
    Joined:
    Sep 25, 2003
    Messages:
    1,131
  8. Apr 28, 2007
    1960willyscj5

    1960willyscj5 Well-Known Member

    Mesa, Arizona
    Joined:
    Nov 27, 2006
    Messages:
    2,793
    You need to re-jet it. High altitude means thinner air, which means you need to compensate for it. The mechanic ought to know that. Jett it for 6k and above. Hang on to the old jets, incase you need to run at low altitudes for any length of time, to keep from running it too lean.:coffee: :hurrican: :)
     
  9. Apr 30, 2007
    Get Dirty

    Get Dirty New Member

    Telluride, CO
    Joined:
    Aug 25, 2005
    Messages:
    22
    well I just compromised and went with the .048s I think that should do the trick. By the way Larry at Automotion was really helpful. Thanks for the input from everyone here. I have got to get some photos up of my jeep here soon, shes a reall beauty.
     
New Posts