Page 1 of 3 1 2 3 LastLast
Results 1 to 10 of 30
  1. #1

    Join Date
    Dec 2012
    Location
    MA
    Posts
    146
    +1
    12

    AFR's all over the place

    I know this subject has been beat to death bu I searched several threads and couldn't find a comparison. I have an 05 RXT and I can't get these AFR's dialed in right, I don't know what I'm doing wrong and I'm hoping you guys can help. The ski has the following mods. all parts are new. x-charger / bosch 42's / Fizzle HE ic / 4" air intake with filter / rrfpr / 15/20R / stock ecu / bosch 02 sensor calibrated. At idle (1800) I'm at 11.4-11.7 at 5000 rpm 13.1-13.4 and at wot 8100 I'm at 12.2-12.4. Fuel pressure at these readings is 56 psi. Now I believe I've that I should be around 13.5 at idle and 13.0 at mid and 11.9-12.2 at wot. I've adjusted this several times run it around and can't get these numbers correct. Today it was around 75 degrees water temp about the 70 or there about, 1/2 tank of fuel and I tare in at 190. I want to try and set this up again sometime in the next couple days so any help is greatly appreciated. On another note this ski accelerates to 8100 incredibly quick and stays right there, should I tweak the impeller? Thanks again
    Last edited by JohnW; 08-26-2013 at 04:14 AM.


  2. #2
    dpracing's Avatar
    Join Date
    Jan 2008
    Location
    Palm Beach, Florida
    Posts
    1,244
    +1
    246
    Quote Originally Posted by JohnW View Post
    I know this subject has been baet to death bu I searched several threads and couldn't find a comparison. I have an 05 RXT and I can't get these AFR's dialed in right, I don't know what I'm doing wrong and I'm hoping you guys can help. The ski has the following mods. all parts are new. x-charger / bosch 42's / Fizzle HE ic / 4" air intake with filter / rrfpr / 15/20R / stock ecu / bosch 02 sensor calibrated. At idle (1800) I'm at 11.4-11.7 at 5000 rpm 13.1-13.4 and at wot 8100 I'm at 12.2-12.4. Fuel pressure at these readings is 56 psi. Now I believe I've that I should be around 13.5 at idle and 13.0 at mid and 11.9-12.2 at wot. I've adjusted this several times run it around and can't get these numbers correct. Today it was around 75 degrees water temp about the 70 or there about, 1/2 tank of fuel and I tare in at 190. I want to try and set this up again sometime in the next couple days so any help is greatly appreciated. On another note this ski accelerates to 8100 incredibly quick and stays right there, should I tweak the impeller? Thanks again
    How are you making afr adjustments? V tech? Motec?

  3. #3
    boost junkie skidoochris's Avatar
    Join Date
    Mar 2012
    Location
    Davison, Mi
    Posts
    4,494
    +1
    476
    my fix would be a rrfpr
    it can lower idle afr and raise wfo afr
    sounds like he has no way to tune it except for fuel psi

  4. #4
    Got Boost? psycho rxp's Avatar
    Join Date
    Jul 2005
    Location
    Port St. Lucie, FL
    Posts
    5,445
    +1
    182
    Yes, you need to pitch prop to get it off the limiter, and u will gain speed in the process. Also a smaller nozzle would help too, like the Riva one. That's why AFR's are erratic. Once off the limiter, set your RRFPR, to get a WOT reading of 11.7-11.9 May need 58psi base. Where ever the idle, and mid range end up, is where they end up.

    Only way to clean it up @ idle and mid, would be with a begi, or CMD fuel controller.

  5. +1 by:


  6. #5
    Matatan tocullo's Avatar
    Join Date
    Nov 2010
    Location
    VISTA AL RIO FL
    Posts
    1,725
    +1
    69
    Quote Originally Posted by psycho rxp View Post
    Yes, you need to pitch prop to get it off the limiter, and u will gain speed in the process. That's why AFR's are erratic. Once off the limiter, set your RRFPR, to get a WOT reading of 11.7-11.9 May need 58psi base. Where ever the idle, and mid range end up, is where they end up.

    Only way to clean it up @ idle and mid, would be with a begi, or CMD fuel controller.
    Exactly!!! Once you have it dial in at WOT ride it like you stole it and don't worry about your low end. I ran that set up for 6 month in the past and my numbers were very similar to your!!

  7. +1 by:


  8. #6
    Banned User
    Join Date
    Aug 2011
    Posts
    5,049
    +1
    238
    He's running an rrfpr fwiw

  9. #7
    dnielsen's Avatar
    Join Date
    May 2008
    Location
    Shreveport, Louisiana
    Posts
    2,018
    +1
    94
    CMD Marine with LCD and WB2 and you'll never have a worry again. Easy install and setup.

  10. #8

    Join Date
    Dec 2012
    Location
    MA
    Posts
    146
    +1
    12
    Skidoochris is right, I'm adjusting afr's with fuel pressure. I have to look into one of the fuel management systems you guys recommend and go from there. At wot @ 8100, I should have explained it a little clearer, the ski is not "bouncing" or "banging" off the limiter, it just goes to 8100 and stays there, no variation, and no change in engine tone at all. Thank you everyone for the information

  11. #9
    Matatan tocullo's Avatar
    Join Date
    Nov 2010
    Location
    VISTA AL RIO FL
    Posts
    1,725
    +1
    69
    IMO. Why spend a $1000 on a fuel managment that the only thing you are going to gain is a little better fuel comsumption! Adjust your WOT with the RRFPR and leave it alone. Ride it and enjoy it! No need for for headaches adding more crap to the boat! Like i said before i ran that almost identical setup for season and loved it, very simple and no much down time!!!!!!

  12. +1 by:


  13. #10

    Join Date
    Dec 2012
    Location
    MA
    Posts
    146
    +1
    12
    tocullo, I think that sounds like the route I'm going to take. I don't race this and honestly the majority of the riding I do is upper mid throttle and wot for maybe 1/2 to maybe a mile and a mile would be a stretch. So I'll just keep and eye on the afr's and do small adjustments as needed, Thanks again for all the information and recommendations guys

Page 1 of 3 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. Speedo all over the place
    By Laxcrazy23 in forum 4-Tec Performance
    Replies: 3
    Last Post: 07-16-2016, 11:03 AM
  2. rxpx et137+4, afrs all over the place, loss of power.
    By 98gsxl951 in forum 4-Tec Performance
    Replies: 52
    Last Post: 05-05-2014, 08:31 AM
  3. Is anyone else's temp display all over the place?
    By bruceg in forum Sea Doo Open Discussion
    Replies: 9
    Last Post: 09-05-2012, 11:27 AM
  4. Speedo bouncing all over the place/staying at 0
    By usrockband in forum 2-Stroke Performance
    Replies: 7
    Last Post: 07-28-2012, 02:15 AM
  5. Rpm all over the place!!!!
    By causeimez in forum 4-Tec Performance
    Replies: 6
    Last Post: 06-20-2011, 10:03 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
  •