Results 1 to 6 of 6
  1. #1

    Should I replace my pistons?

    All 3 of my pistons measure 3.9330".
    The new spec is 3.9350-3.9360.
    The limit is 3.9290.

    Piston wall clearance is .0037, .0037 & .0036". (#1,#2,#3)
    The new spec is .0009-.0022.
    The limit is .0039.

    Cylinder taper is .0001" in all 3 cylinders.
    Taper limit is .0011.

    Cylinder roundness is .0002" in all 3 cylinders.
    Cylinder roundness limit is .0006.

    All above measurements were taken at the positions specified in the teardown manual.

    Can I just go with a re-hone, and new rings? Or should I go with a re-hone and new pistons & rings? Or should I have the cylinders bored out 1mm over with new pistons and rings? 170 hours on the motor.

    Thanks,

    Mark


  2. #2
    xBigDaddyx117's Avatar
    Join Date
    Oct 2008
    Location
    Florida
    Posts
    366
    well if the motor has 170 hours on it I dont think its worn that much, unless those hours where hell.

  3. #3
    The most interesting man in the world. Nils888's Avatar
    Join Date
    Jun 2005
    Location
    California
    Posts
    4,231
    +1
    1,043
    I would go to the oversize pistons!!

  4. #4
    jpeconsult's Avatar
    Join Date
    Jul 2007
    Location
    Pineville, LA
    Posts
    5,448
    +1
    1
    Quote Originally Posted by Nils888 View Post
    I would go to the oversize pistons!!
    I would do whatever Nils suggests.

  5. #5
    The most interesting man in the world. Nils888's Avatar
    Join Date
    Jun 2005
    Location
    California
    Posts
    4,231
    +1
    1,043
    I was just making a suggestion on the pistons. 170 hours on stock bores. From his measurements everything is borderline worn out. The logical thing to do would be to go to the Factory oversize pistons and bore the block.

  6. #6
    It will cost you a set of pistons and rings to find out, if you should have bored it. You can bore it next time!!! Just kidding you don't want this thing to come apart and ruin the entire engine. Always lean on the safe side if there is doubt.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Replacing my 07 RXT- What should I get
    By abrx7 in forum 4-Tec Performance
    Replies: 5
    Last Post: 06-17-2015, 10:42 AM
  2. Replies: 9
    Last Post: 04-20-2015, 09:37 PM
  3. RXP-X - Should I replace all my clamps?
    By Jarrett in forum 4-Tec Performance
    Replies: 5
    Last Post: 10-07-2009, 08:24 PM
  4. should I replace pistons or keep stock
    By fobxgpr in forum Yamaha PWC Performance (2-stroke)
    Replies: 2
    Last Post: 07-30-2008, 10:28 PM
  5. look at my pistons(efi guru's)
    By txgp1300r in forum Yamaha PWC Performance (2-stroke)
    Replies: 6
    Last Post: 08-11-2006, 09:27 AM

Posting Permissions

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