Results 1 to 3 of 3

Thread: 440 Ring gap?

  1. #1
    Race, wreck, repeat delagem's Avatar
    Join Date
    Aug 2006
    Location
    Homer, NY
    Posts
    728
    +1
    2

    440 Ring gap?

    I'm tearing into the motor on my '89 440 to find out why I don't have very good compression, about 80/90. I pulled the jug and pistons, took off the rings, and checked the clearance between the piston and cylinder w/ a feeler gauge, shows .06mm, which is fine according to my service manual.

    The problem is, my manual doesn't list ring end gap! I checked it, and came up with .7mm, which is way big I think. Does anyone know what this gap should be?

    I'm a little concerned about the compression, as the piston isn't the problem, and I'm using the same battery and compression gauge in another 440, where it's around 130/130. Could just that ring gap cause this?


  2. #2

    Join Date
    Apr 2005
    Location
    Michigan
    Posts
    274
    +1
    1
    0.2-0.4mm standard value
    0.7mm service limit
    Last edited by 1FastTrespiper; 01-13-2007 at 06:46 PM. Reason: correction

  3. #3

    Join Date
    Apr 2005
    Location
    Michigan
    Posts
    274
    +1
    1
    While your at it pull the flywheel cover. If the flywheel and the inside of the flywheel cover look oiley, the front crank seal is bad.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. WARNING:Ring gap interference inspection!
    By w/rpm500 in forum Yamaha Old School Skis
    Replies: 0
    Last Post: 10-26-2009, 06:11 PM
  2. ring gap
    By RHeller1 in forum Yamaha PWC Performance (2-stroke)
    Replies: 2
    Last Post: 07-27-2009, 06:23 PM
  3. impeller and wear ring gap
    By mustang5x0 in forum 4-Tec Performance
    Replies: 6
    Last Post: 07-04-2008, 01:07 PM
  4. gp1200r ring gap
    By rolo2230 in forum Yamaha Open Discussion
    Replies: 4
    Last Post: 12-30-2007, 07:44 PM
  5. wear ring gap? how much?
    By JLewis in forum Yamaha Open Discussion
    Replies: 5
    Last Post: 06-13-2007, 07:35 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
  •