Results 1 to 5 of 5

Thread: Max Bore Size

  1. #1

    Max Bore Size

    I have a 900 ZXI cylinder with some scoring. According to the service manual it is at the service limit (74mm). Standard bore is 73 mm and the manual says you can overbore by up to 1 mm (aka 74mm dia.).

    I noticed that several piston kits are sold (Wiseco, WSM) that are 74.5mm and are specified for this model. I was wondering if anyone had overbored their cylinders to do this before or if anyone knows if that is a down right bad idea.

    Any input is appreciated.

    Thanks.


  2. #2
    thesepaperwings's Avatar
    Join Date
    May 2007
    Location
    South East Kansas
    Posts
    1,283
    +1
    1
    Bad idea, they will fit but the walls are pretty thin and you run into issues.

  3. #3
    Thanks for the reply. That's what I figured. What kind of issues in particular do you mean? (cracked cylinder, broken pistons, etc?)

  4. #4
    thesepaperwings's Avatar
    Join Date
    May 2007
    Location
    South East Kansas
    Posts
    1,283
    +1
    1
    The cooling transfer is uneven and you can get ring gouges real fast.

  5. #5
    Cool. The only reason I asked was because mine is bored to the max and is in need of repair and it is cheaper to buy a new cylinder on ebay than to resleeve this one. So, I figured I would see if boring the one I have was possible before purchasing a different jug. I've got one coming UPS today.

    Thanks for the input.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Running two diffrent bore sizes
    By xplayer2885 in forum Polaris Open Discussion
    Replies: 2
    Last Post: 06-14-2008, 12:28 AM
  2. max bore size on a sleeved cyl
    By goose in forum Yamaha PWC Performance (2-stroke)
    Replies: 1
    Last Post: 04-03-2008, 09:42 PM
  3. Diffrent bore sizes.
    By xplayer2885 in forum Polaris Open Discussion
    Replies: 6
    Last Post: 08-17-2007, 09:56 PM
  4. Stock bore size on sl750?
    By Rodneyae in forum Polaris PWC Performance
    Replies: 4
    Last Post: 12-11-2006, 08:52 PM
  5. Throttle Body bore size
    By HOSS in forum 4-Tec Performance
    Replies: 23
    Last Post: 05-09-2006, 12:13 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
  •