Results 1 to 4 of 4
  1. #1

    2003 GP800R question

    I have a 2003 GP800R. I purchased it this year and it only had 33 hours on it. For about the first 6 times I took it to the lake, it would run 65 mph according to the instrument cluster and do a 7500 rpm. Now it seem like it will run about 57 and 6500 rpm. I have changed the plugs and put in a new fuel filter. I checked the speed with a GPS and WOT it 50 mph. Any idea why it's not running like it did? It has 63 hours on it now. It is completly stock. I checked the compression and the front cyclinder has 115 and the rear has 90.

  2. #2
    25 psi difference between two cylinders is a lot! Recheck compression.

    Does the 800 model have a Catalytic converter? If yes, there is another possible power loss, these Cat con fail early on the three cylinders models

  3. #3
    Plus, you cant compare a 65mph reading on an OEM speedometer to the 50 mph reading you got with a GPS. Im pretty sure your real top speed with that stock ski should be below 60mph using an accurate instrument like a GPS or Radar

  4. #4
    mudslanger's Avatar
    Join Date
    Jul 2010
    Huntsville Al
    It would be a good idea to recheck the compression at wide open throttle if you still have only 90 psi on the rear cylinder it would be a good idea to pull the head and inspect the piston and cylinder walls also check the power valve for damage and proper movement.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. 2003 gp800r
    By jdt1003 in forum Yamaha PWC Performance (2-stroke)
    Replies: 5
    Last Post: 09-19-2011, 04:45 PM
  2. WTB Yamaha GP800R HULL - 2003 ~ 2004
    By cerebral in forum Yamaha Classifieds
    Replies: 4
    Last Post: 09-01-2010, 10:18 PM
  3. GP800R Piston Question
    By Awamori in forum Yamaha PWC Performance (2-stroke)
    Replies: 1
    Last Post: 10-01-2009, 07:49 AM
  4. 2003 Gp800R Help
    By smace in forum Yamaha PWC Performance (2-stroke)
    Replies: 9
    Last Post: 05-27-2008, 10:37 AM
  5. Yamaha GP800R Question?
    By Amyandbrandon2005 in forum Yamaha Open Discussion
    Replies: 5
    Last Post: 09-01-2007, 02:22 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