Results 1 to 7 of 7
  1. #1
    Banned User
    Join Date
    Jun 2010
    Location
    Milwaukee WI
    Posts
    16,708
    +1
    1,324

    Domestic piston ID

    I am trying to determine what size pistons I have in my engine. I have a piston that I know is standard and it has 74,39 stamped on the top of it. The others I have are stamped 74,64. Am I to assume that is the piston size, with the larger number being .25MM over the standard. I need to get 2 new pistons and I need to figure out what size to get. the end gap on the standard rings when I put it into my cylinder measures .039 so I am guessing that my cylinders are .25MM over


  2. #2
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
    Join Date
    Oct 2006
    Location
    Cleveland OH
    Posts
    17,330
    +1
    31
    Are the cyls damaged and needing bored?

    Are you going to have them honed?

    If so, ask the machine shop doing the work to measure them for you. And then order the pistons.

  3. #3
    Banned User
    Join Date
    Jun 2010
    Location
    Milwaukee WI
    Posts
    16,708
    +1
    1,324
    They just need to be honed.

  4. #4
    urugol's Avatar
    Join Date
    Nov 2009
    Location
    Sydney, Australia
    Posts
    1,231
    +1
    3
    If you are going to use the one I sent you it will need to be re bored as it is the standard size 74.39. If I had know I would have sent you an oversize one I have I thought you were going standard You won't be able to use the new rings I sent you either

  5. #5

    Join Date
    Jun 2008
    Location
    Bullhead City AZ.
    Posts
    451
    +1
    2
    What is it a Polaris 900 there 74.50 as per the wiseco book

  6. #6
    Banned User
    Join Date
    Jun 2010
    Location
    Milwaukee WI
    Posts
    16,708
    +1
    1,324
    Turns out I have oversize cylinders and pistons, and 2 pistons need to be replaced.....It looks like I will just get them bored 1 mm over and get new pistons and be done with it....

  7. #7

    Join Date
    Jun 2008
    Location
    Bullhead City AZ.
    Posts
    451
    +1
    2
    sell those 900 cylinders ans bolt on a set of 1050 cylinders and domes, jet the carbs and run with it.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Anybody know how to ID the piston size from a 1300?
    By jpa1300 in forum Yamaha Open Discussion
    Replies: 9
    Last Post: 10-10-2013, 05:29 PM
  2. What causes a MAG piston seizure on a domestic?
    By bgaidan in forum Polaris Open Discussion
    Replies: 21
    Last Post: 03-14-2011, 09:10 PM
  3. 1300R Piston Size Id?
    By jaywaite in forum Yamaha PWC Performance (2-stroke)
    Replies: 2
    Last Post: 08-19-2010, 11:14 AM
  4. FS Wiseco std. piston set for sl 650 and boyeson reeds for domestic
    By 1FASTXC in forum Polaris Classifieds
    Replies: 1
    Last Post: 07-02-2010, 08:13 AM
  5. Domestic 700 Pistons same as Domestic 1050 Pistons?
    By PolarisSLTX1050 in forum Polaris Open Discussion
    Replies: 8
    Last Post: 10-27-2009, 02:59 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
  •