Results 1 to 8 of 8
  1. #1
    krouchchocolate's Avatar
    Join Date
    Nov 2009
    Location
    Houston, TX
    Posts
    1,224
    +1
    53

    Weird compression #'s?

    Getting weird compression readings on my ski. Cylinder 1/2/3 120/130/140. Anyone ever had this problem? Seems like a leak down test would be the best thing for me to do to figure out why I am getting inconsistent numbers.

    My recent upgrades on my ski are Ferrea Valves, Riva Valvetrain, ET 140R SC, Bosch 48lb injectors, and XS IC. My afr's are @ idle=13.5, midrange = 12.5, WOT=11.7. After I had installed my new head gasket and did my timing each cylinder compression was reading about 140/145/140

    However when I was tuning the ski, it was running pig rich. About 10.5 at idle, 11 at midrange, and 10.5 at wot when i had the reference line connected. I fixed the problem by removing the reference line.


  2. #2
    krouchchocolate's Avatar
    Join Date
    Nov 2009
    Location
    Houston, TX
    Posts
    1,224
    +1
    53
    Forgot to mention that ski has been running great. Getting around 8020-8100 rpms at WOT. Just this inconsistent compression numbers is scaring me as I finally just got my ski running great and I don't feel like wrenching on it until winter.

  3. #3
    monaroman76's Avatar
    Join Date
    Mar 2008
    Location
    Whyalla, South Australia
    Posts
    1,979
    +1
    28
    Have you run it plenty since changing the valves? Were the valve seats done when installing the valves? Was your engine warm when you compression tested it?

  4. #4
    krouchchocolate's Avatar
    Join Date
    Nov 2009
    Location
    Houston, TX
    Posts
    1,224
    +1
    53
    put about 20 hours on the ski now. slow91 was the one who installed the valves and did the valve job for me so it was done right.

  5. #5
    Bob 1tommygunner1927's Avatar
    Join Date
    Apr 2007
    Location
    Houston, Texas
    Posts
    6,366
    +1
    977
    Khoa......check the cam gear/timing. It may have slipped some, retarding the timing even more. Set the timing straight up. Get rid of the stock ECU.

  6. #6
    Having Fun jp1300r's Avatar
    Join Date
    Sep 2005
    Location
    Florida
    Posts
    5,334
    +1
    261
    However when I was tuning the ski, it was running pig rich. About 10.5 at idle, 11 at midrange, and 10.5 at wot when i had the reference line connected. I fixed the problem by removing the reference line.[/QUOTE]


    This doesn't make sense to me. I know what you saw on the AFR gauge, but like I said doesn't make sense. Maybe I am missing something.

  7. #7
    krouchchocolate's Avatar
    Join Date
    Nov 2009
    Location
    Houston, TX
    Posts
    1,224
    +1
    53
    Quote Originally Posted by jp1300r View Post
    However when I was tuning the ski, it was running pig rich. About 10.5 at idle, 11 at midrange, and 10.5 at wot when i had the reference line connected. I fixed the problem by removing the reference line.

    This doesn't make sense to me. I know what you saw on the AFR gauge, but like I said doesn't make sense. Maybe I am missing something.[/QUOTE]

    i don't remember what the numbers were exactly but when i had the reference line connected on my rrfpr. i could never get the afr correct at wot

  8. #8
    Water4fire's Avatar
    Join Date
    May 2005
    Location
    New Braunfels TX.
    Posts
    10,062
    +1
    790
    Was the motor cold when tested? Drop a few drops of oil in #1 and see what happes.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. weird compression levels, & moisture in cylinder 1...
    By My09RXPX in forum 4-Tec Performance
    Replies: 2
    Last Post: 06-22-2014, 05:35 AM
  2. Compression test, are the #'s weird here???
    By GP1300R powerhouse in forum Yamaha PWC Performance (2-stroke)
    Replies: 10
    Last Post: 05-30-2007, 07:14 AM
  3. lost compression on all cylinders
    By mxl16 in forum 4-Tec Performance
    Replies: 36
    Last Post: 12-03-2005, 05:15 PM
  4. a bit of a weird problem, can I have opinions please???
    By rxp_boy in forum 4-Tec Performance
    Replies: 9
    Last Post: 11-15-2005, 01:39 PM
  5. Whooops... only getting 116 compression!?
    By Phil in forum 4-Tec Performance
    Replies: 7
    Last Post: 09-04-2005, 03:55 PM

Posting Permissions

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