Page 1 of 10 1 2 3 ... LastLast
Results 1 to 10 of 95
  1. #1

    ULTRA 300X a new custom mod !!!

    Hi all

    i'm from Kuwait and just bought the 300x , am an autotech and i own a shop over here to modify and tune high performance cars such as vettes,fords,porsches, not a ski pro but i like to mess with everything has a four stroke engine lol.

    as you know the ski only makes 13-14 psi not 17 as they advertised.i made a custom pulley and tested it made 19-20psi but since the ski isn't tuned i adjusted the bov to vent at 15psi.the ecu didnt have a limit and this is a good thing so with a fuel managment system to add more fuel the ski will waiting on my custom meth system from alkycontrol to arrive and then this will solve the lean issue for a while until someone makes a FMS.the the stock belt fits perfect and didnt nees a smaller belt either.

    ran 72mph with riva bypass,R&D grate,free flow and riva water box (13psi) was 33c water temp 32c air temp) @7800rpm.

    going to install the air intake,ride plate , meth,and turn it up to 18-19psi.then will see what happens.

    when i said lean issue this is not from running more boost. A/F was the same from running the 13 psi or 19 psi or using the slo key at 7 psi it was lean 12.5-12.9. dont know why they tuned it this way not like autos they come on the rich side from the factory.but it doesnt matter am using a 94 octane pump gas and with 8.4 cr wont hurt it, but keep it safe better so i will turn it up when i install the meth system.

    here are some pics of the custom pulley on the left and the stock one on the right
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	IMG00262-20110630-1925.jpg 
Views:	340 
Size:	76.7 KB 
ID:	244160   Click image for larger version. 

Name:	IMG00263-20110630-1925.jpg 
Views:	250 
Size:	70.2 KB 
ID:	244161  

  2. #2
    here's a pic of the AEM A/F gauge installed on the glove box
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	IMG00269-20110702-1429.jpg 
Views:	683 
Size:	66.9 KB 
ID:	244162  

  3. #3
    Quote Originally Posted by Kawikwt View Post
    > as you know the ski only makes 13-14 psi not 17 as they advertised.
    > i made a custom pulley and tested it made 19-20psi
    > 13-14 psi - Is that what you saw on the dash meter boost gauge or actual measured boost from a separate pressure gauge?
    > 19-20 psi - How did you measure this?

  4. #4
    Banned User
    Join Date
    Jan 2009
    Now all I need is for you to send me your account info and I'll give u one fir free lol

  5. #5
    This was on a separate boost gauge was also close to the stock dash

  6. #6
    Olomana's Avatar
    Join Date
    Jan 2011
    Tahiti, French Polynesia
    Good to see more car people coming on PWC!

  7. #7
    nicjak's Avatar
    Join Date
    Mar 2008
    Warragul, Downunder
    spinning the motor any faster is only asking for trouble jmpo

  8. #8
    My name is Sean and I am addicted to STXs smokeysevin's Avatar
    Join Date
    May 2008
    piston speed is what matters, rpm is only a part of the calculation. It will be interesting to see how the new blower handles the extra rpm, the old one couldnt take much more than stock for very long. Have you tried pulling the stock fuel pressure regulator and installing an adjustable one?


  9. #9
    Watch out for excessive blowby condition with increased engine rpm & boost pressure.
    How many hours on your ski when you did the pulley mod for 19-20 psi?

  10. #10
    It has 29 hours, blowby wont be a problem if you know how to let the engine breath well it doesnt matter engine speed or more boost wont hurt it, the smaller pulley will spin the blower faster without the need of having more rpm because it's a root not a centuri , so my rpm is still the same but i'm making more boost at the same rpm.blowby is just when you start to have something going wrong with your engine , weak rings,knock,or engine not breathing well,thats why they have the catchcan installed.i built alot of engines so i know what am doig dont worry.

Page 1 of 10 1 2 3 ... LastLast

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. New Kaw Ultra 300x cutting out at 5k RPM. NEED HELP
    By Shelbyelite in forum Kawasaki PWC Performance (4-stroke)
    Replies: 91
    Last Post: 03-26-2018, 03:08 PM
  2. FX SHO or Ultra 300x New to the site!!
    By Bad Behavior in forum Yamaha PWC Performance (4-stroke)
    Replies: 82
    Last Post: 02-15-2012, 02:30 AM
  3. FS R & D Ultra 300X/300LX 2011/2012 New ride plate! in water twice!
    By Hurricane1000 in forum Kawasaki Classifieds
    Replies: 1
    Last Post: 01-31-2012, 02:16 PM
  4. ultra 300x.a mod to add hp and cut down on oil consumption and improve ring seal.
    By 300XXX in forum Kawasaki PWC Performance (4-stroke)
    Replies: 16
    Last Post: 08-16-2011, 04:34 PM
  5. ultra 300x custom exaust video
    By elpeladodelsamba in forum Kawasaki PWC Performance (4-stroke)
    Replies: 7
    Last Post: 07-11-2011, 07:46 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