Page 5 of 6 FirstFirst ... 3456 LastLast
Results 41 to 50 of 60
  1. #41
    mittens's Avatar
    Join Date
    Mar 2018
    Location
    Huntsville, AL
    Posts
    1,327
    +1
    147
    Quote Originally Posted by Green Hulk View Post
    Not at all, it's not an ignition cut like with the older skis. The ECU closes off the throttle when approaching the limiter. Also while we are on this subject, if your ski has a bounce at full throttle it's highly likely it's on the limiter. The ski will bounce as the throttle closes/opens rapidly to keep off the limiter.
    Hmm will be super interesting to see the new prop NOT tweaked and see what RPMs and how ski handles it this makes me think I maybe on the limiter. as the most I EVER see is 9360 rpms. but should be 9500 limiter.


  2. #42
    Reaper9789's Avatar
    Join Date
    Jul 2014
    Location
    Canyon Lake, TX
    Posts
    810
    +1
    105
    Quote Originally Posted by Green Hulk View Post
    Not at all, it's not an ignition cut like with the older skis. The ECU closes off the throttle when approaching the limiter. Also while we are on this subject, if your ski has a bounce at full throttle it's highly likely it's on the limiter. The ski will bounce as the throttle closes/opens rapidly to keep off the limiter.
    I have a datalog of my ski hitting 10,332rpm and the throttle is still fully open.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	rpm.jpg 
Views:	241 
Size:	153.8 KB 
ID:	481028  

  3. #43
    JESUS G's Avatar
    Join Date
    Jun 2007
    Location
    South Florida
    Posts
    609
    +1
    210
    On Yamaha, there is a few limiters, but basically these are the most important.

    REV LIMITER : ECU cut the ignition off ( If you are hitting the rev limiter you wont get the sped you should , this happens in any brand and model, Yamaha, Sea-Doo, Kawa)

    BOOST LIMITER: ECU close off the throttle , enough to keep the boost under the limit value ( We remove this limiter in all the tunes )

    SPEED LIMITER: Actually is sort of a rev limiter. Yamaha kind of calculate that at certain RPM you will get around 68mph, depend on what model, changes from 7200 to 7400 approx. So once you get pass those RPM, after a couple of seconds approx, the ECU close the throttle enough to keep the RPMs where the limit is set.


  4. #44
    mittens's Avatar
    Join Date
    Mar 2018
    Location
    Huntsville, AL
    Posts
    1,327
    +1
    147
    So with a aftermarket tune (I have deans team) but I know both of you have worked together before so I would bet can answer a basic question like this.

    I would think I would feel/ hear the ignition cut at 9500 & it not just get close & be happening. & as far as boost & speed limits they should be removed as well with a turbo tune.

  5. #45
    MSX 150 guy lives on Mr. GP1800's Avatar
    Join Date
    Jun 2010
    Location
    Milwaukee WI
    Posts
    18,034
    +1
    1,600
    Here’s what I’m curious about. Is this new generation of GP really that much faster than the previous version? I seem to recall the previous version if the GP being around 86 mph on a stage 2 setup. As far as I know the bottom hull is still the same thing between the 2 versions. Any input as far as what the differences are that would make the new version faster?

  6. #46

    Join Date
    Apr 2021
    Posts
    8
    Quote Originally Posted by Mr. GP1800 View Post
    Here’s what I’m curious about. Is this new generation of GP really that much faster than the previous version? I seem to recall the previous version if the GP being around 86 mph on a stage 2 setup. As far as I know the bottom hull is still the same thing between the 2 versions. Any input as far as what the differences are that would make the new version faster?
    160 transom plate plus intake grate and ride plate differences could explain it.

  7. #47

    Join Date
    Apr 2021
    Posts
    8
    Quote Originally Posted by mittens View Post
    So with a aftermarket tune (I have deans team) but I know both of you have worked together before so I would bet can answer a basic question like this.

    I would think I would feel/ hear the ignition cut at 9500 & it not just get close & be happening. & as far as boost & speed limits they should be removed as well with a turbo tune.
    You can see it if you data log. I see RPM data just over the limit followed by an RPM drop well below the limit. Not obvious when on the ski.

  8. #48
    Click avatar for tech links/info K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    45,788
    +1
    2,615
    Quote Originally Posted by Randy P View Post
    Ö just over the limit followed by an RPM drop well below the limit.

    Not obvious when on the ski.
    When I first started using the Riva MaptunerX I had a Stage 1 (or 1 Plus) tune with 8000RPM limit on GP1800. Sometimes when the conditions were just right the SVHO engine could reach that 8000 level. On flat water I could see the tach touch 8000 and then drop down a few hundred RPM, then ramp back up.

    The limiter effect on engine power was quite gentle and if I was not watching the tachometer I would not know the limiter was engaging.

  9. #49
    xkon's Avatar
    Join Date
    Jun 2017
    Location
    Houston
    Posts
    206
    +1
    36
    Quote Originally Posted by Mr. GP1800 View Post
    Hereís what Iím curious about. Is this new generation of GP really that much faster than the previous version? I seem to recall the previous version if the GP being around 86 mph on a stage 2 setup. As far as I know the bottom hull is still the same thing between the 2 versions. Any input as far as what the differences are that would make the new version faster?
    I think its just this stage "2" has an extra 400 rpms than what most people when were referencing in the past for gp1800 stage 2 Riva's tunes. This stage 2 is the 9200 rpm limit and the other stage 2 tunes are 8800 rpm limit.

  10. #50
    mittens's Avatar
    Join Date
    Mar 2018
    Location
    Huntsville, AL
    Posts
    1,327
    +1
    147
    Well this will be interesting when I drop a few RPMs with new prop and see what ski picks up or not.

Page 5 of 6 FirstFirst ... 3456 LastLast

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. FS 2009 yamaha fzr riva stage 3 fully built
    By snipe243 in forum Yamaha 4 Stroke Skis
    Replies: 0
    Last Post: 08-16-2019, 11:32 AM
  2. F/s Riva stage 2 ported 63m motor. Built by Tim judge
    By waverider1200 in forum Yamaha Old School Skis
    Replies: 8
    Last Post: 04-09-2013, 03:53 PM
  3. Riva stage III built finally here!!!
    By abracadabra in forum Yamaha PWC Performance (4-stroke)
    Replies: 300
    Last Post: 09-23-2011, 04:43 PM
  4. FS 2009 RIVA Stage 3 FZR + + + Fully built motor
    By stangbang in forum Yamaha 4 Stroke Skis
    Replies: 11
    Last Post: 06-09-2011, 01:32 PM
  5. Riva built Stage III+ FZR
    By 1 FAST VE in forum Yamaha PWC Performance (4-stroke)
    Replies: 69
    Last Post: 09-28-2010, 01:33 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
  •