Slow jets...

Discussion in '1st & 2nd Generation 1983-1989' started by savedrider, Jan 8, 2007.

  1. savedrider

    savedrider New Member

    Joined:
    Nov 10, 2006
    Messages:
    202
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Southern California
    I rebuilding my carbs and have two of them apart so far. While checking/cleaning I have also been noting the jetting to make sure all the jets are correct. The slow jets I have pulled so far are both marked 38, but when I look through them the ID is noticeably different (one bigger than the other). I don't think one is blocked up with debris, but I'm wondering what's going on.

    Maybe the previous owner replaced one as one looks to be a different vintage than the other due to the condition of the brass and the stamping located in different places. At any rate, something doesn't seem right. I stuck the one with the smaller diameter in a bucket of carb dip overnight and I will blow it out tomorrow to see, but I don't think it will help. Unless someone drilled the jet shouldn't a Keihin 38 be a Keihin 38? :confused:
     
    Last edited: Jan 8, 2007
  2. Ferris

    Ferris New Member

    Joined:
    Dec 2, 2006
    Messages:
    121
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Nashville, Tennessee
    Yes, a 38 should be a 38 - unless it is a very old jet.

    Old - as in, pre-CV model Keihin jets are different sizes than their more modern brethren, even if they are stamped with the same numbers. I ran into this problem in reverse - I needed jets for the old mechanical style carbs on my brother's AHRMA Suzuki race bike, and earned this knowledge the hard way.

    If it doesn't turn out to be crud in the jet, you need new ones.
     
  3. savedrider

    savedrider New Member

    Joined:
    Nov 10, 2006
    Messages:
    202
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Southern California
    Thanks! Your feedback really helps.
     
  4. savedrider

    savedrider New Member

    Joined:
    Nov 10, 2006
    Messages:
    202
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Southern California
    Well I'm about to go crosseyed from staring at tiny little pinholes in jets! :biggrin:

    I have all 4 slow jets removed and cleaned now. They are all marked 38, but per my naked eye two are a smaller diameter and two are a larger diameter. I'm not sure what's going on here. 3 of them are stamped with the 38 marking in the same spot and 1 isn't. I don't know if this is significant or not.

    I have found some of these jets locally and decided I will pick up 2 of them and compare to what I have. I should be able to make one matching set that way.
     
  5. restlesswildman

    restlesswildman New Member

    Joined:
    Aug 19, 2006
    Messages:
    9
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Cincinnati, Ohio
    you could always pick up a set of drill indexs or gauge pins to check hole dia. Just remember to be careful not to gouge the hole and make it bigger. Also to stop going cross eyed get a set of jeweler magnifying glasses.
     
  6. savedrider

    savedrider New Member

    Joined:
    Nov 10, 2006
    Messages:
    202
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Southern California
    Thanks for the tips wildman. I grabbed two new jets and was able to match them up with two I had. They ended up being the smaller size. I'm not sure if someone drilled them or gouged them out on accident while cleaning. I'm finding a lot of "interesting" things with these carbs as I'm going through them.
     
Related Topics

Share This Page