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  1. #1
    Member
    Join Date
    Mar 2006
    Location
    NJ
    Posts
    3,058

    USA Are these compression numbers acceptable-Yamaha 225 0x66?

    Looking at a 2002 ' low to mid hours Yamaha 225 VMAx 3.1 liter OX66 outboard.
    We just did compression test and came up with the following readings :
    110,110,110,113,115,116. I wanted to get a general consensus from guys on the board that have had the same motor if those compression test readings seem acceptable or too low and you would absolutely not touch this Yamaha. The motor is on a ZX 225 Skeeter -that has been dealer maintained with paperwork for the past 5 years. Very light use -maybe 15 days in past three years. If you have any suggestions on whether I should run ring free and Yama lube that would be good to know as well ?


    Thank you for your advice and opinions -Creekchub.

  2. Member
    Join Date
    Jul 2014
    Location
    KALKASKA MICHIGAN
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    4,124
    #2
    They look good to me. But find somebody with a borescope and have a look in the cylinders. That will tell you a lot also. Not a fan of Yamalube as it burns dirty. I run a full synthetic and Sea foam a couple of times a year with ring free every tank. CJ
    2002 X19 200HP OX66 HO Vmax,HPDI lower, it lives, thanks Hydro Tec.

  3. #3
    Those are fine. All are within 10% as they should be. Yes, run Ring Free and Stabil in every tank. Also put on a 10 micron filter if there is none now. I run Pennzoil 100% synthetic but a blend is also good. Not a fan of Yamalube.
    BassinBarrister
    2001 ChampioN 206 Elite
    225 Yamaha VMax EFI
    25P Trophy Plus Prop

  4. Member
    Join Date
    Jul 2014
    Location
    Chesterfield VA
    Posts
    3,402
    #4
    I second good numbers. My 200hp was lower, all in the 102-105 range I believe it was (done a couple of years ago now) and I was told they are fine too. Main thing is that they are all close.
    Kevin | 2000 Champion 19​1 | 2000 Yamaha OX66 200hp