Results 1 to 4 of 4

Thread: gp800

  1. #1
    Randy11023's Avatar
    Join Date
    Aug 2008
    Location
    Kearney Missouri
    Posts
    134

    gp800

    I got a 99 gp800 last week (141hrs) and the compression running about 119 and 122 which seem low. I was going to put a new top end in it and some wave eater clips. Since this is a two stroke end I wonder if it like a dirt bike in away. I mean I work on bikes alot and we rebuild them every 6month and year mark. Six month replace the ring and piston at a year.

    Anyways the re some I think it low because dirt bikes run about 135 to 150 stock. Since it is just the top end I would like to now what you have to do on these. On bikes I just break the glaze on the cylinder with fine grand sandpaper clean the PV and check clearance of the ring and lube up the cylinder with some oil.

    Also in riding and racing for years I always used wiesco pistons them wear great and also really help the rev out alot weight is a big different from stock oem pistons. But I see alot people use OEM piston in there boat (pro-x and WSM)

    Thanks
    Randy


  2. #2
    billy's gpr's Avatar
    Join Date
    Mar 2007
    Location
    central coast...nsw...australia
    Posts
    295
    +1
    1
    120 psi is no low for that ski,you could pull the head and take a look,maybe get the head decked to up the comp a bit 140-150psi,these run chrome bore and require a diamond hone,and oem piston are genrally the best to run

  3. #3
    Randy11023's Avatar
    Join Date
    Aug 2008
    Location
    Kearney Missouri
    Posts
    134
    Thanks so 120 is not to low?? I just fig since I will have the topend off to just replace them.

  4. #4
    Buaidh No Bas howestek's Avatar
    Join Date
    May 2005
    Location
    Louisiana
    Posts
    917
    120 isn't too low.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. why does the gp800 tun such low compresion
    By w-nut in forum Yamaha PWC Performance (2-stroke)
    Replies: 10
    Last Post: 11-05-2006, 10:23 PM
  2. gp800:gp1200 ?
    By blaster800 in forum Yamaha PWC Performance (2-stroke)
    Replies: 8
    Last Post: 09-29-2006, 09:58 PM
  3. GP800 only running on one cylnder... why?
    By rnq124 in forum Yamaha PWC Performance (2-stroke)
    Replies: 5
    Last Post: 09-23-2006, 10:04 AM
  4. 98 gp800 impeller selection for max speed
    By spyder3000gtvr4 in forum Yamaha PWC Performance (2-stroke)
    Replies: 9
    Last Post: 09-10-2006, 05:51 PM
  5. Help rebuilding a 98 GP800
    By Jamie13 in forum Yamaha PWC Performance (2-stroke)
    Replies: 3
    Last Post: 02-19-2006, 02:11 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
  •