Page 1 of 2 1 2 LastLast
Results 1 to 10 of 13

Thread: low rpm again!!

  1. #1
    tysonfzr's Avatar
    Join Date
    Nov 2009
    Location
    johor bahru malaysia
    Posts
    621

    low rpm again!!

    2day i took out the S/C b1 again follow the instruction again,fix it back still the same rpm at 5000 without power shot n wif power shot is abt 4500.we took off the j pipe attach to the throttle body rev n feel below, the pressure is like sucks not powerful at all...the spark plug is like black as charcoal so change new spark plug still got the same result...when the rpm is at below 2000 u can feel the power but when rev the power begin to lack n stop at 5000 n the power seems heavy...now i took out everything,power cooler,b1,BOV n i dun knw wat cause the problem,can any1 tell me wat i should do next?


  2. #2
    Boilerman Bill BPnta's Avatar
    Join Date
    Jun 2008
    Location
    Yulee, FL
    Posts
    887
    +1
    1
    Quote Originally Posted by tysonfzr View Post
    2day i took out the S/C b1 again follow the instruction again,fix it back still the same rpm at 5000 without power shot n wif power shot is abt 4500.we took off the j pipe attach to the throttle body rev n feel below, the pressure is like sucks not powerful at all...the spark plug is like black as charcoal so change new spark plug still got the same result...when the rpm is at below 2000 u can feel the power but when rev the power begin to lack n stop at 5000 n the power seems heavy...now i took out everything,power cooler,b1,BOV n i dun knw wat cause the problem,can any1 tell me wat i should do next?
    Have you tried it in the water yet? On the trailer you are limited by the ECU to 5000 RPM for your SC compressor's safety.

    Also- on the trailer the motor is experiencing VERY little load so the power output is gonna be tiny, even if you revved it to 10,000 RPM.

    Think about it. When the motor is experiencing zero load it takes very little energy (fuel) to turn it. Little fuel means little air also, so the throttle valve will be throttled back MUCH further to retrict the air going in at comparable RPMs.

    This is why you are limited in the trailer. With the throttle restricted, this creates a low flow situation for the SC compressor since it's output is correllated with RPM and not engine load. The low flow creates what is called "surge".

    Hope this helps and if you've been on the water and had the same problem just disregard it

  3. #3
    RUSH.'s Avatar
    Join Date
    Aug 2007
    Location
    Orlando
    Posts
    868
    +1
    17
    Quote Originally Posted by tysonfzr View Post
    2day i took out the S/C b1 again follow the instruction again,fix it back still the same rpm at 5000 without power shot n wif power shot is abt 4500.we took off the j pipe attach to the throttle body rev n feel below, the pressure is like sucks not powerful at all...the spark plug is like black as charcoal so change new spark plug still got the same result...when the rpm is at below 2000 u can feel the power but when rev the power begin to lack n stop at 5000 n the power seems heavy...now i took out everything,power cooler,b1,BOV n i dun knw wat cause the problem,can any1 tell me wat i should do next?


    Check your reverse gate switch.

  4. #4
    Bounty Hunter Carlos Thomas's Avatar
    Join Date
    Jul 2007
    Location
    San Leandro, CA
    Posts
    1,401
    +1
    22
    I had this problem with my Honda once. On the trailer is rev'd fine. In the water it was about 4,000 rpms. It was a hose that came loose. There were no flashin lights or error codes. I have seen other boats have this problem. The hose that came loose for me was one of the hoses that connects to the intercooler.

  5. #5

    Join Date
    Aug 2008
    Location
    Southern Florida
    Posts
    5,589
    +1
    345
    Is there a learners mode on those skis?

  6. #6
    tysonfzr's Avatar
    Join Date
    Nov 2009
    Location
    johor bahru malaysia
    Posts
    621
    Quote Originally Posted by BPnta View Post
    Have you tried it in the water yet? On the trailer you are limited by the ECU to 5000 RPM for your SC compressor's safety.

    Also- on the trailer the motor is experiencing VERY little load so the power output is gonna be tiny, even if you revved it to 10,000 RPM.

    Think about it. When the motor is experiencing zero load it takes very little energy (fuel) to turn it. Little fuel means little air also, so the throttle valve will be throttled back MUCH further to retrict the air going in at comparable RPMs.

    This is why you are limited in the trailer. With the throttle restricted, this creates a low flow situation for the SC compressor since it's output is correllated with RPM and not engine load. The low flow creates what is called "surge".

    Hope this helps and if you've been on the water and had the same problem just disregard it
    how come my spark plug is like black as charcoal?

  7. #7
    It's not the destination, it's the journey!! Rip'nTear SHO's Avatar
    Join Date
    Apr 2008
    Location
    Ft. Lauderdale
    Posts
    4,573
    Sounds like either an intake hose is not connected and you have a boost leak or u have a dead SC clutch. Put it in the water and see what she does.....you really shouldnt be revving that ski on the trailer like that.

  8. #8
    tysonfzr's Avatar
    Join Date
    Nov 2009
    Location
    johor bahru malaysia
    Posts
    621
    Quote Originally Posted by Rip'nTear SHO View Post
    Sounds like either an intake hose is not connected and you have a boost leak or u have a dead SC clutch. Put it in the water and see what she does.....you really shouldnt be revving that ski on the trailer like that.
    the hose is not loose,wat do mean by SC clutch?fzr have clutch?

  9. #9
    It's not the destination, it's the journey!! Rip'nTear SHO's Avatar
    Join Date
    Apr 2008
    Location
    Ft. Lauderdale
    Posts
    4,573
    Quote Originally Posted by tysonfzr View Post
    the hose is not loose,wat do mean by SC clutch?fzr have clutch?
    Yes...you have a clutch on your SC.....ur SC wheel should only spin in 1 direction...if it spins the other way too when bolted to the engine...then you have a bad clutch

  10. #10
    tysonfzr's Avatar
    Join Date
    Nov 2009
    Location
    johor bahru malaysia
    Posts
    621
    the clutch is it located below the super charger?the 1 wif the gear?i did use my hand to turn the gear below it turn only 1 direction,the clutch is it inside?

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. Low RPM's
    By RedRyderRXP in forum 4-Tec Performance
    Replies: 13
    Last Post: 08-13-2006, 07:48 PM
  2. 06 rxp low rpm
    By rxpenpastu in forum Sea Doo Open Discussion
    Replies: 1
    Last Post: 07-21-2006, 02:25 PM
  3. Low RPM Issue
    By xenonx in forum 4-Tec Performance
    Replies: 11
    Last Post: 06-19-2006, 03:19 PM
  4. fixing my low rpm's
    By MDGPR in forum Yamaha PWC Performance (2-stroke)
    Replies: 4
    Last Post: 06-17-2006, 08:26 PM
  5. New 04 RXP Low RPM & Speed
    By RXP04 in forum 4-Tec Performance
    Replies: 0
    Last Post: 07-02-2005, 09:12 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
  •