Page 1 of 5 1 2 3 ... LastLast
Results 1 to 10 of 48
  1. #1
    TDR's Avatar
    Join Date
    Nov 2009
    Location
    Melbourne, Australia
    Posts
    727
    +1
    10

    Smile Seadoo 951 70MPH??

    Hi Guys,

    At the moment i have these mods in the ski:

    ADA racing head 50cc Domes
    Prok Flame arrestors
    Worx intake grate
    solas 15/20 prop << needs repitching
    GPS 59.1MPH < props fault 6800-6900RPM

    over the winter i would like to get my ski to go around 70mph and beat all those RXP's

    Im just having trouble to find what mods i need to do this, if any one could help me with some little mods to increase by 1mph it would be a great help.

    Thanks Nick


  2. #2
    Work Harder, Millions on Wellfare Depend On Us! ultramaxracing05's Avatar
    Join Date
    Aug 2009
    Location
    Beaumont, Texas
    Posts
    2,999
    +1
    123
    Unless you drop in a 4tec and remove the 951 maybe, but 70 on a 951 XP...Not possible
    this has been discussed before.

    are you rejetted by the way?
    fill in your rideplate holes.

    I believe the stock impeller works great,
    and the stock grate also.
    You should be seeing speeds of around 62-64 but you must have overkilled something.

    You should read Bens 951 Mods, its got some good info.

  3. #3
    TDR's Avatar
    Join Date
    Nov 2009
    Location
    Melbourne, Australia
    Posts
    727
    +1
    10
    Ok thanks for your help, what about Bore setup??

  4. #4
    Work Harder, Millions on Wellfare Depend On Us! ultramaxracing05's Avatar
    Join Date
    Aug 2009
    Location
    Beaumont, Texas
    Posts
    2,999
    +1
    123
    Quote Originally Posted by TDR View Post
    Ok thanks for your help, what about Bore setup??
    read my edited comment

  5. #5
    TDR's Avatar
    Join Date
    Nov 2009
    Location
    Melbourne, Australia
    Posts
    727
    +1
    10
    Quote Originally Posted by ultramaxracing05 View Post
    Unless you drop in a 4tec and remove the 951 maybe, but 70 on a 951 XP...Not possible
    this has been discussed before.

    are you rejetted by the way? Nope
    fill in your rideplate holes. Thanks for the Tip

    I believe the stock impeller works great,
    and the stock grate also.
    You should be seeing speeds of around 62-64 but you must have overkilled something. Will do

    You should read Bens 951 Mods, its got some good info.
    Thanks for the tips

  6. #6
    Work Harder, Millions on Wellfare Depend On Us! ultramaxracing05's Avatar
    Join Date
    Aug 2009
    Location
    Beaumont, Texas
    Posts
    2,999
    +1
    123
    You need to rejet. the ski is most likely running lean. I'm running pro-k also, I'm at sea level and current jet size is Main 162.5(stock) Pilots 90. Needle Seat 2.0(stock) the factory Pilots are 75.0 so thats a big difference. There might be mixed opinions about jetting some ppl run 85 Pilots.

    Do a compression check just be safe, I believe that running the ski with stock jets and ProK is not really healthy for an engine.

    I'm not an expert on Big Bores but the rule of thumb is "The more modding you do, the reliability will decrease" "For every action there is a reaction"

  7. #7
    m schmidt's Avatar
    Join Date
    Mar 2007
    Location
    East, Tn.
    Posts
    235
    +1
    2
    Quote Originally Posted by ultramaxracing05 View Post
    Unless you drop in a 4tec and remove the 951 maybe, but 70 on a 951 XP...Not possible
    this has been discussed before.

    are you rejetted by the way?
    fill in your rideplate holes.

    I believe the stock impeller works great,
    and the stock grate also.
    You should be seeing speeds of around 62-64 but you must have overkilled something.

    You should read Bens 951 Mods, its got some good info.
    Yes it's possible, DONE THAT. Use the stock grate.

  8. #8
    SURFnTURF's Avatar
    Join Date
    May 2007
    Location
    Australia
    Posts
    878
    +1
    11
    Quote Originally Posted by TDR View Post
    Hi Guys,

    At the moment i have these mods in the ski:

    ADA racing head 50cc Domes
    Prok Flame arrestors
    Worx intake grate
    solas 15/20 prop << needs repitching
    GPS 59.1MPH < props fault 6800-6900RPM

    over the winter i would like to get my ski to go around 70mph and beat all those RXP's

    Im just having trouble to find what mods i need to do this, if any one could help me with some little mods to increase by 1mph it would be a great help.

    Thanks Nick
    70 mph with some descent reliability from a 951 based engine is not achievable.They are just too stressed to take that punishment.

    To geta little more from your set up remove the grate and install the stock one as the worx grate pulls the hull down too much into the water and then loads the pump with too much water for the prop to process.

    The solas prop is too tall for you horsepower output,If you want to use that prop , have it repitched it to 14/19 or the stock prop pitched up a degree or so.
    Your jetting with prok's should be lows 87.5 highs 165 , stock N/seat with accelerator pumps installed.Mixture screws set at Lows out 1.5 turns,highs closed.
    If no pumps are used 95 lows 165 highs with same settings.
    I always remove the internal filters in the carbs and leave the stock choke plates operational.
    Your current set up should pull good from low to mid range but falls flat at the high rev range,with this set up it will pull right through to 7000-7050 with a stock prop.
    If the prop is too tall you wont have enough power to spin it up to the correct rev range.This is when aftermarket pipes are required as they will allow the engine to rev more and at the same time produce more torque which then can turn taller pitched props.

    As a comparison I have an XPL 951 engine bored 1mm O/Size with offset bores and stock head (140 comp) rinnaldi reeds,miller 10mm spacers
    with shortened stock intake runners (10 mm) with with the rev limiter raised to 7500 and curve retarde rate changed, stock carbs set as above with a 97.5 pipe and manifold with a lightened flywheel , PTO outer weight removed with prok's and this will turn 7300-7340 .This is set up for surf riding not top speed but this ski will maybe get to 65mph on a good crisp day.The beauty with this boat is that it is super reliable and will get me home at the end of the day.Reliability is peace of mind.

  9. #9
    TDR's Avatar
    Join Date
    Nov 2009
    Location
    Melbourne, Australia
    Posts
    727
    +1
    10
    When you say High needle screw closed you mean all the way in, wouldnt this be starving the motor of fuel at high speeds

  10. #10
    Rampage's Avatar
    Join Date
    Sep 2007
    Location
    Holland, Michigan, United States
    Posts
    2,932
    I would say that the money you would put into even TRYING to get that ski to 70 would be more then just buying an RXP...

Page 1 of 5 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. Ben's Secret Mods for Seadoo 951 and 1050 setups
    By YudLuz2 in forum 2-Stroke Performance
    Replies: 8
    Last Post: 07-30-2008, 01:18 PM
  2. WTB: Seadoo 951 Silver Motor Parts
    By fast96HX in forum Sea Doo Classifieds
    Replies: 13
    Last Post: 07-05-2008, 02:51 PM
  3. Seadoo 951 Reed Cages
    By jetcar123 in forum 2-Stroke Performance
    Replies: 2
    Last Post: 03-07-2008, 04:54 PM
  4. Seadoo 951/947 carbs on a GPR?
    By yamadoo2 in forum Yamaha PWC Performance (2-stroke)
    Replies: 1
    Last Post: 02-15-2007, 10:37 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
  •