Results 1 to 5 of 5
  1. #1

    GP1300r compression test

    I'm buying a gp1300r and would like to know the correct procedure for doing a compression test on this particular boat. Is there anything special you have to do, like giving it full throttle?

  2. #2
    "Hustler" Inkaddict's Avatar
    Join Date
    Aug 2007
    Welcome to GH... Be sure and check out all the amazing information in the awesome search feature... Every question you can think of has probably been answered a dozen different times...

    click here for the answer...

  3. #3
    jb1300r's Avatar
    Join Date
    Sep 2009
    If every cylinder is above 110 psi then its in good shape, and they should all be right around that, if one is 10psi or lower then it has a one way ticket to needing a rebuild. A compression test is easy, just pop out the spark plugs, hold the throttle open, and hit the starter until the gauge will not move anymore and there you have the compression of that cylinder.

  4. #4

  5. #5
    One other variable i didnt see listed....
    Some (economical) compression testers will have the shrader valve at the gauge end of the hose.. These will read lower compression numbers because of the added volume the hose allows.
    To read correct cylinder compression the shrader valve needs to be on the cylinder head end of the hose, which will eliminate added CCs from the volume of the hose, which can be 10-15 pounds or more, depending on the length of the hose.
    On a hose with a shrader valve at the gauge end of the hose, the longer the hose, the lower the compression.
    Check your gauge and hose, and find the shrader valve, so you know what you have.
    Not to be confused with the gauge pressure release valve usually mounted on the gauge itself.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. How To: Compression Test
    By Red Devil in forum 4-Tec Performance
    Replies: 9
    Last Post: 06-01-2007, 12:05 AM
  2. Compression test, are the #'s weird here???
    By GP1300R powerhouse in forum Yamaha PWC Performance (2-stroke)
    Replies: 10
    Last Post: 05-30-2007, 07:14 AM
  3. Steps on doing a compression test on a 2 stroke?
    By Rxp BLazin in forum Yamaha PWC Performance (2-stroke)
    Replies: 10
    Last Post: 05-04-2007, 09:43 AM
  4. Proper Engine Compression Testing !!!
    By RX951 in forum Yamaha How To & FAQs
    Replies: 2
    Last Post: 08-20-2006, 06:36 PM
  5. 06 GP1300R Compression 130psi ?
    By Johnjet in forum Yamaha PWC Performance (2-stroke)
    Replies: 8
    Last Post: 01-22-2006, 10:29 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