pxctoday

» Log in

User Name:

Password:

Not a member yet?
Register Now!

» Find OEM Parts

» Jobs

» wallpapers

Page 2 of 6 FirstFirst 1234 ... LastLast
Results 11 to 20 of 57
  1. #11
    PWCToday.com Is My Home Away From Home fastgtfairlane's Avatar
    Join Date
    Apr 2010
    Location
    charlotte,nc
    Age
    34
    Posts
    3,240

    Re: 650sx FPP running problems

    i would close the bottom and middle and just open the top for best bottom end. try 3/4 turn on the top screw. it will keep the head pipe cooler for better bottom end. the bottom screw allows the headpipe to run a little warmer which will raise the rpm hit up and less bottom end but will give more rpms on top. your bottom screw being open is probably where the loading up is coming from because when the ski sits the water gravity feeds down and with that bottom screw open its letting water into the exhaust stream when the ski is off.

    if you really want to increase the bottom end, run a dedicated cooling line to the pipe so youre getting fresh cooler water directly from the pump and not first preheated through the engine. then run a flow control valve which will limit water going into the water box at lower rpms. then you could close your screw a little more and still get good bottom and top end power. with this setup on my 550 with a tunable factory headpipe setup, i had the bottom and middle screw closed and the top just 1/2 a turn.
    Last edited by fastgtfairlane; 10-03-2017 at 09:16 PM.
    91 440; PJS Viper 7000, jetsport exhaust mani, factory full pipe, coffman waterbox,solas 17*, jetco worked 440 pump, ocean pro nozzles. shredmaster ocean rideplate and grate combo, wide tray, footholds, deep strake mod, driveshaft fill,650sx quick turn

    build thread part 1: http://www.pwctoday.com/showthread.php?t=331343
    build thread part 2: http://www.pwctoday.com/showthread.php?t=364872
    build thread part 3: http://www.pwctoday.com/showthread.php?t=396154

  2. #12
    PWCToday Regular 92Kawasaki750SS's Avatar
    Join Date
    Jul 2015
    Location
    United States
    Age
    33
    Posts
    127

    Re: 650sx FPP running problems

    Well, just did compression check and I have like 190 in front cylinder ( stock milled head by NewMiller earlier this season ) and only 50 or so in rear cylinder. Pulled the head and see absolutely to reason for loss of compression. What should I check?

    Sent from my SM-N920V using Tapatalk
    Last edited by 92Kawasaki750SS; 10-03-2017 at 09:25 PM.

  3. #13
    PWCToday.com Is My Home Away From Home BLRider's Avatar
    Join Date
    Apr 2007
    Location
    SE MI
    Age
    54
    Posts
    9,463

    Re: 650sx FPP running problems

    How does the cylinder wall look in the rear cylinder?
    Never argue with an idiot, they will drag you down to their level then beat you with experience.

  4. #14
    PWCToday Regular 92Kawasaki750SS's Avatar
    Join Date
    Jul 2015
    Location
    United States
    Age
    33
    Posts
    127

    Re: 650sx FPP running problems

    It doesn't looks really bad, but it deffinetly looks worse than the front. There are more lines in it, looking like the rings starting to score. I don't know jet skis well but my only other thought would be the reeds broke or something for that cylinder. I re-installed and torqued the head and got the exact same reading as stated above. I might check the reeds tomorrow but I'm thinking it's time for a new top end. I have put about 30 hrs or so on this thing in two seasons and 20 or so have been with the high compression head this season. And I haven't been exactly nice yo this poor old thing.

    Sent from my SM-N920V using Tapatalk

  5. #15
    PWCToday Regular 92Kawasaki750SS's Avatar
    Join Date
    Jul 2015
    Location
    United States
    Age
    33
    Posts
    127

    Re: 650sx FPP running problems

    Ok, so before I take the cylinders off I'm gonna do a leakdown test to check for any major leaks and see if the crank seals are good. Anything else I should do before removal?

    Sent from my SM-N920V using Tapatalk

  6. #16
    PWCToday.com Is My Home Away From Home fastgtfairlane's Avatar
    Join Date
    Apr 2010
    Location
    charlotte,nc
    Age
    34
    Posts
    3,240

    Re: 650sx FPP running problems

    might get lucky and just have to hone the cylinders. i recently bought a 750 small pin that had low compression in one of the cylinders but i didnt see any bad spots on the cylinder walls. just ordered new pistons with rings, and top end bearings and just went through the entire engine and had a friend do a quick cylinder hone. has equal compression now and is running strong. since you know one cylinder has low compression, cheap insurance would be to go ahead and put in new crank seals as well. no real need to do a leak down test if you already have low compression on 1 cylinder.
    Last edited by fastgtfairlane; 10-04-2017 at 03:07 PM.
    91 440; PJS Viper 7000, jetsport exhaust mani, factory full pipe, coffman waterbox,solas 17*, jetco worked 440 pump, ocean pro nozzles. shredmaster ocean rideplate and grate combo, wide tray, footholds, deep strake mod, driveshaft fill,650sx quick turn

    build thread part 1: http://www.pwctoday.com/showthread.php?t=331343
    build thread part 2: http://www.pwctoday.com/showthread.php?t=364872
    build thread part 3: http://www.pwctoday.com/showthread.php?t=396154

  7. #17
    PWCToday Regular 92Kawasaki750SS's Avatar
    Join Date
    Jul 2015
    Location
    United States
    Age
    33
    Posts
    127

    Re: 650sx FPP running problems

    But why split the lower crank case if the seals don't leak? And IF the piston looks good I may just do rings. Idk yet, I also HATE doing things twice and not doing thing right the first time. This engine is 26 years old and never been rebuilt so maybe it's time for new rubber seals.

    Sent from my SM-N920V using Tapatalk

  8. #18
    PWCToday Regular 92Kawasaki750SS's Avatar
    Join Date
    Jul 2015
    Location
    United States
    Age
    33
    Posts
    127

    Re: 650sx FPP running problems

    Rings and hone cylinder at the least....

  9. #19
    PWCToday.com Is My Home Away From Home fastgtfairlane's Avatar
    Join Date
    Apr 2010
    Location
    charlotte,nc
    Age
    34
    Posts
    3,240

    Re: 650sx FPP running problems

    if those are the original crank seals and you are pulling the cylinder apart, why wouldnt you do the seals when youre that much apart? seems like cheap insurance to me. being those are the original seals i wouldnt waste the time doing a leak check. probably a little more than 2 hours to split the cases, clean everything and reinstall. then youll 100% know it couldnt be an issue. i think i spent just over 300 bucks for a complete top end kit pistons, rings, bearings and complete gasket kit with seals. wouldnt use anything other than oem kawi gaskets. partzilla.com has all oem kawi stuff. i went with sbt cast pistons on mine just because a buddy owns a jetski shop and i got his discounts.
    Last edited by fastgtfairlane; 10-04-2017 at 03:26 PM.
    91 440; PJS Viper 7000, jetsport exhaust mani, factory full pipe, coffman waterbox,solas 17*, jetco worked 440 pump, ocean pro nozzles. shredmaster ocean rideplate and grate combo, wide tray, footholds, deep strake mod, driveshaft fill,650sx quick turn

    build thread part 1: http://www.pwctoday.com/showthread.php?t=331343
    build thread part 2: http://www.pwctoday.com/showthread.php?t=364872
    build thread part 3: http://www.pwctoday.com/showthread.php?t=396154

  10. #20
    PWCToday Regular 92Kawasaki750SS's Avatar
    Join Date
    Jul 2015
    Location
    United States
    Age
    33
    Posts
    127

    Re: 650sx FPP running problems

    Ok yeah, I'll look into it. I've got all winter now. Any suggestion on sealer for the lower case halves?

    Sent from my SM-N920V using Tapatalk

Page 2 of 6 FirstFirst 1234 ... LastLast

Thread Information

Users Browsing this Thread

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

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Powered by vBadvanced CMPS v4.2.0