Results 1 to 4 of 4
  1. #1

    Compressure ratio yamaha

    Hi what should be the compessure ratio be on yamaha J500A be, and how low can it be to use?


  2. #2
    Old Ski Insanity w/rpm500's Avatar
    Join Date
    Aug 2005
    Location
    Crystal River Fl
    Posts
    2,208
    my book says, o/e new 142 lbs...both cylinders within 15 psi of each other..more than say a 10% loss (around 125), I would think about pulling the head and inspect..

  3. #3
    Quote Originally Posted by w/rpm500 View Post
    my book says, o/e new 142 lbs...both cylinders within 15 psi of each other..more than say a 10% loss (around 125), I would think about pulling the head and inspect..
    Okey thanks, they are littlebit over 120psi so I dont have to worrie so much. Maybe next year I will take the motor apart.
    So I have to look at the electrial thing now, isnt it behind the flywheel where it speed up the ignition on the sparkplugs?

  4. #4
    Old Ski Insanity w/rpm500's Avatar
    Join Date
    Aug 2005
    Location
    Crystal River Fl
    Posts
    2,208
    the box is mounted on the hatch opening rh side,above the water box it has the solinoid cdi, coil and fuse in it... regulator is mounted on the side extermally... your windings are under the flywheel ... most of these will test individually , but if im remembering correctly you can test some once the leads in electical box are accesable...(sp)

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Should I Run 30:1 Or 40:1 Premix Ratio In My 98'Yamaha XL1200
    By DanielDucati in forum Yamaha PWC Performance (2-stroke)
    Replies: 6
    Last Post: 06-09-2013, 08:58 PM
  2. ratio for riva yamaha
    By thomase87 in forum Yamaha Old School Skis
    Replies: 12
    Last Post: 04-01-2009, 02:59 PM
  3. I now have a Yamaha forum
    By Green Hulk in forum Sea Doo Open Discussion
    Replies: 4
    Last Post: 11-21-2008, 11:02 AM
  4. New Yamaha Models
    By JFizzleJR in forum Sea Doo Open Discussion
    Replies: 1
    Last Post: 08-27-2005, 10:44 AM
  5. 2006 Yamaha's
    By boataddict in forum Sea Doo Open Discussion
    Replies: 10
    Last Post: 08-24-2005, 04:54 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
  •