Page 1 of 2 1 2 LastLast
Results 1 to 10 of 12
  1. #1

    Stage 3ish ski problems; 74mph!

    Hey guys, i don't post much however i need some help, After i got my rotax ecu installed the ski was running great 8400rpm getting 79 on radar, but lately it has been a dog. The ski now will not pass 8150rpm, at 74mph, i have not sucked up anything into the pump,the wear ring seems fine, i get a little cavitation on startup, however the ski still pops out of the water. The ski definitely seems less responsive especially in midrange power. I have no idea what has happened for me to loose this power.


    I have noticed that my catch can is almost full, how often should it be drained? lastly if i shut down the ski after a 15min ride it takes about 40 seconds of cranking the engine over to restart the ski!, i have also notice the after the ecu upgrade the exhaust tips seem to get a black film over them rather quick.


    Thanks in advance.


    04 rxp

    mods

    Rotax ecu
    sc wheel (Custom wheel)
    50 pound injectors
    Fpr
    duel exhaust
    9 inch k&n intake
    lightweight retainers and springs
    opas pro block off
    intercooler
    prop (not sure of brand)
    Last edited by Snoman; 08-23-2009 at 06:21 PM.


  2. #2
    West Texas RXP skoepp's Avatar
    Join Date
    Oct 2007
    Location
    west texas
    Posts
    12,019
    +1
    149
    Check sc slip.

    You got way to much blow bye if your filling up can per tank. Fueling issues, or some other engine issues.
    Have you tested your skis AFR. It sounds like you could be running way to rich and is why does not want to start at idle when warm.

  3. #3
    Quote Originally Posted by skoepp View Post
    Check sc slip.

    You got way to much blow bye if your filling up can per tank
    Sorry i dont understand what you mean, but ya i have not checked the a/f ratio, but that is deff next on my to do list.

  4. #4
    camar0's Avatar
    Join Date
    Apr 2007
    Location
    Sunshine
    Posts
    787
    what fuel pressure base do you have it set at?

  5. #5
    Banned User
    Join Date
    Jul 2006
    Location
    Ft.Lauderdale
    Posts
    3,237
    if your blowing oil in the catch can, check your compression.. You might have bad rings

  6. #6
    speedskixp's Avatar
    Join Date
    Feb 2008
    Location
    venice fl.
    Posts
    8,117
    +1
    120
    Bro, with that rr ecu and the 50s you really need a duel reg or a fuel controller. Idle and mid range will be very rich without it. We have a boat set-up very similar and with a 60 lb base it idles in the mid 10s wich is very rich and will dilute your oil causing it to overfill and fil the catch can pretty quick. It can also cause hard starting and a miss and rough idle. You really need to check your A/F.
    When you say custom wheel, is it a 70-142.5 or do you know?

  7. #7
    Quote Originally Posted by camar0 View Post
    what fuel pressure base do you have it set at?
    I have no idea, i did not do the work on the ski, however i will try to find out.

    Quote Originally Posted by Alex13 View Post
    if your blowing oil in the catch can, check your compression.. You might have bad rings


    Quote Originally Posted by speedskixp View Post
    Bro, with that rr ecu and the 50s you really need a duel reg or a fuel controller. Idle and mid range will be very rich without it. We have a boat set-up very similar and with a 60 lb base it idles in the mid 10s wich is very rich and will dilute your oil causing it to overfill and fil the catch can pretty quick. It can also cause hard starting and a miss and rough idle. You really need to check your A/F.
    When you say custom wheel, is it a 70-142.5 or do you know?

    Well i do have a rising fuel rate pressure regulator, and i was told that is all i would need. Now if there were gas in the oil, would there not be a milky residue?

  8. #8
    Gotta love this sport! 05Limited's Avatar
    Join Date
    Apr 2005
    Location
    Stockton, CA
    Posts
    2,677
    +1
    4
    Mike... I hope I'm wrong, but what you are describing (oil in catch can, slowing of ski, hard starting) sure sounds like bad rings. I'd do a compression check to hopefully rule out this notion... but you may find a weak cylinder or two... and most likely the rear cylinder.

  9. #9
    Richieb's Avatar
    Join Date
    Oct 2008
    Location
    Sydney, Australia.
    Posts
    1,001
    Also sounds like mixture too rich.

  10. #10
    ya i hear what you guys are saying, i will do a compression test and report back, what degree of compression should i be looking for? just something to think about, when i do a cold start the ski starts just fine, but when i the engine is warm it is hard to start. Now if the engine is warm should there not be a better seal between the rings and the piston? thus the engine starting better when at temp?

Page 1 of 2 1 2 LastLast

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. stage 3 BOV problems?
    By masta2000 in forum 4-Tec Performance
    Replies: 12
    Last Post: 08-24-2009, 07:37 AM
  2. 2005 GTX SC Stage I w/ problems
    By jpeconsult in forum 4-Tec Performance
    Replies: 79
    Last Post: 01-18-2008, 04:57 PM
  3. Replies: 9
    Last Post: 04-19-2006, 07:06 PM
  4. 06 Ski problems
    By BlackHawk in forum 4-Tec Performance
    Replies: 43
    Last Post: 04-13-2006, 01:02 PM
  5. riva stage 1 kit problems
    By macattack in forum 4-Tec Performance
    Replies: 3
    Last Post: 06-28-2005, 05:08 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
  •