Results 1 to 8 of 8

Thread: Boost variance

  1. #1
    Phil's Avatar
    Join Date
    May 2005
    Location
    Smith Mountain Lake, VA
    Posts
    1,428
    +1
    23

    Boost variance

    We are just breaking in my wife's Ultra. It is a great riding ski. It cuts turns great and handles the wakes with ease. I took it really easy for the first 2 hours and followed all the break-in rules. At this point, Ultra250Tn suggested we do some pulls to seat the valves better. We now have 2.5 hours on it. I did 3 pulls from 20-50mph and noticed that the boost was only going to 10. The rpms hit 7,200 instantly and I got off it after about 2-3 seconds. I hoped it would go to 11.3 as advertised, but it didn't. Did anybody else have this same experience?

    My friend has a blue 250 and his definitely pulls harder than ours. However, I remember doing this with his ski when the barometer was 30.5 and lake temp was 76F. I thought that roots blowers are not that effected as much by lower barometric conditions as are the Sea Doo SCs. Today, the air temp was 86F, the lake temp was 86F, it rained later in the day and the barometer was 29. These are really bad conditions for jet skis. BTW - My RXT kicked my Ultra's butt yesterday in the pull contest! At this point I am somewhat disappointed in the Ultra.

    I want to buy an accurate boost gauge and adaptor for testing. Does anybody know where I get buy a really good one?


  2. #2
    Formerly Ultra250 TN Aquaholic6801's Avatar
    Join Date
    Feb 2007
    Location
    Old Hickory,Tn
    Posts
    5,446
    +1
    650
    Actually you have a short window to seat the valves, like the first 20 mins of riding, after that they pretty much as seated as they are going to get, you may try the BOV adjustment adjust to see if you get an extra bar of 2 of boost.

  3. #3
    way2fast's Avatar
    Join Date
    May 2005
    Location
    Melbourne Beach, FL
    Posts
    4,009
    +1
    4
    Quote Originally Posted by Phil View Post
    We are just breaking in my wife's Ultra. It is a great riding ski. It cuts turns great and handles the wakes with ease. I took it really easy for the first 2 hours and followed all the break-in rules. At this point, Ultra250Tn suggested we do some pulls to seat the valves better. We now have 2.5 hours on it. I did 3 pulls from 20-50mph and noticed that the boost was only going to 10. The rpms hit 7,200 instantly and I got off it after about 2-3 seconds. I hoped it would go to 11.3 as advertised, but it didn't. Did anybody else have this same experience?

    My friend has a blue 250 and his definitely pulls harder than ours. However, I remember doing this with his ski when the barometer was 30.5 and lake temp was 76F. I thought that roots blowers are not that effected as much by lower barometric conditions as are the Sea Doo SCs. Today, the air temp was 86F, the lake temp was 86F, it rained later in the day and the barometer was 29. These are really bad conditions for jet skis. BTW - My RXT kicked my Ultra's butt yesterday in the pull contest! At this point I am somewhat disappointed in the Ultra.

    I want to buy an accurate boost gauge and adaptor for testing. Does anybody know where I get buy a really good one?

    The "pulls" you speak of are to seat the piston rings, not the valves. Getting off of it after 2-3 seconds doesn't prove much...probably not enough time for the stock gauge to respond to the true boost put out by the SC or to give a comparison as to the Ultra vs your RXT. give it some time to break in, things should improve.


    Richard

  4. #4
    Phil's Avatar
    Join Date
    May 2005
    Location
    Smith Mountain Lake, VA
    Posts
    1,428
    +1
    23
    Quote Originally Posted by way2fast View Post
    The "pulls" you speak of are to seat the piston rings, not the valves. Getting off of it after 2-3 seconds doesn't prove much...probably not enough time for the stock gauge to respond to the true boost put out by the SC or to give a comparison as to the Ultra vs your RXT. give it some time to break in, things should improve.
    Richard
    Ok, now I have 4.5 hours on the ski. This morning I made about 1/2 dozen pulls from 20-58mph. Getting out of the hole is pretty slow. Kathy's stock RXT kicks its butt. So does Doug's Ultra. Does the hole shot improve over time or is this it?

  5. #5
    Phil's Avatar
    Join Date
    May 2005
    Location
    Smith Mountain Lake, VA
    Posts
    1,428
    +1
    23
    Quote Originally Posted by Ultra250 Tn View Post
    Actually you have a short window to seat the valves, like the first 20 mins of riding, after that they pretty much as seated as they are going to get, you may try the BOV adjustment adjust to see if you get an extra bar of 2 of boost.
    Is the Ultra's gauge accurate?

  6. #6

    Join Date
    Aug 2005
    Location
    Salinas CA
    Posts
    451

    Wink

    Quote Originally Posted by Phil View Post
    Ok, now I have 4.5 hours on the ski. This morning I made about 1/2 dozen pulls from 20-58mph. Getting out of the hole is pretty slow. Kathy's stock RXT kicks its butt. So does Doug's Ultra. Does the hole shot improve over time or is this it?
    It sounds like you have the cavitation problem most 250X`s suffer from.
    Mine did it too.
    I bought the pump seal kit for 89.00 bucks from R-Rated and solved the problem 100% Call Rudy @ 1-732-606-1163...

  7. #7
    Formerly Ultra250 TN Aquaholic6801's Avatar
    Join Date
    Feb 2007
    Location
    Old Hickory,Tn
    Posts
    5,446
    +1
    650
    Quote Originally Posted by Ultra250 Tn View Post
    Actually you have a short window to seat the valves, like the first 20 mins of riding, after that they pretty much as seated as they are going to get, you may try the BOV adjustment adjust to see if you get an extra bar of 2 of boost.
    Yeah what Richard said, I wasnt paying attention, lol.RINGS!

  8. #8
    way2fast's Avatar
    Join Date
    May 2005
    Location
    Melbourne Beach, FL
    Posts
    4,009
    +1
    4
    Quote Originally Posted by Phil View Post
    Ok, now I have 4.5 hours on the ski. This morning I made about 1/2 dozen pulls from 20-58mph. Getting out of the hole is pretty slow. Kathy's stock RXT kicks its butt. So does Doug's Ultra. Does the hole shot improve over time or is this it?

    Phil; See my post about the silicone. Bet that is your problem.

    Rich

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. ultra 300 boost variance
    By ronaldsons in forum Kawasaki Open Discussion
    Replies: 5
    Last Post: 04-27-2014, 02:38 AM
  2. Octane Boost???
    By RM_RXP in forum 4-Tec Performance
    Replies: 20
    Last Post: 05-27-2007, 08:08 AM
  3. Boost gauge, Gps, Depth Gauge ideas
    By Mark S in forum 4-Tec Performance
    Replies: 45
    Last Post: 04-17-2006, 09:59 PM
  4. boost guage
    By INDY27 in forum 4-Tec Performance
    Replies: 29
    Last Post: 10-25-2005, 08:23 AM
  5. Digital Boost guage
    By Sunfunzoom in forum 4-Tec Performance
    Replies: 7
    Last Post: 05-13-2005, 12:51 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
  •