Results 1 to 10 of 10

Thread: attn yamaguru's

  1. #1

    attn yamaguru's

    maybe someone here could shed some light on this problem. i built an 03 1300 for a customer with the following mods.
    - riva 150 psi heads
    - flame arrestor
    - efi controller set at 6617
    - d plate
    - cat chip
    - 14/20 dynafly with 06 pump
    i tested it and ran 72 mph @7160 rpm.
    customer went out on it and seized the rear piston after 1 hr.
    i rebuilt it with 3 new pistons because 1 and 2 were .010" clearance(well out of spec)
    i also learned the customer was using 87 octane so i figured that may be the cause.
    filled with 93 octane and retested. ran great.
    custome took it and rode around slowly breaking it in. gave it full throttle and seized within seconds. rear cylinder again. pulled it apart. rear piston has rich looking burn pattern but does have minor deto pecking.
    i have checked...
    engine leak test...ok
    crank phase....# 3 is .010" higher in bore than #2 with #1 @tdc(ok imo)
    compression before failure 155 psi
    what am i missing? what are some of the common parts to fail on this thing? i assume at this point it is fuel related but not sure

    thanks
    mark


  2. #2
    Dirty Sanchez's Avatar
    Join Date
    Dec 2005
    Location
    Northern Virginia
    Posts
    1,038

    efi guru

    Mark, try to get a hold of wfo. Feel free to call me. I know a little. I'll send you a pm

  3. #3
    It could be a bad controller. I would use a Free Flow and make sure to run 5 pounds less on the 3rd cylinder head and dump the water on this cylinder overboard . When you say rich looking burn pattern, you meant ...No wash at all?? You did say that he seized at WOT???

    Have you presssure tested the water jacket system.

    Which flame arrestor???

  4. #4
    Hydrotoys's Avatar
    Join Date
    Jul 2005
    Location
    Mesa, AZ
    Posts
    16,712
    +1
    85
    -Water ingestion would be my first guess.
    -Pressure test the engine. Could have a blown rear seal.
    -Cylinder base gasket on 180deg out (but the other two would be bad.)
    -Injector issue or someother FI issue.

  5. #5
    WE DONT DIAL 911 RDH's Avatar
    Join Date
    Jan 2007
    Location
    LAKE TRAVIS
    Posts
    1,862
    how long did the customer break the ski in for before giving it full throttle?

  6. #6
    Hydrotoys's Avatar
    Join Date
    Jul 2005
    Location
    Mesa, AZ
    Posts
    16,712
    +1
    85
    Did you have the rear cylinder re-nikisil'd or just replaced it with a new one?

  7. #7
    Quote Originally Posted by Fercho View Post
    It could be a bad controller. I would use a Free Flow and make sure to run 5 pounds less on the 3rd cylinder head and dump the water on this cylinder overboard . When you say rich looking burn pattern, you meant ...No wash at all?? You did say that he seized at WOT???

    Have you presssure tested the water jacket system.

    Which flame arrestor???
    it has a free flow exhaust and a riva flame arrestor(no outerwear). he rode around for about 45 min varying the throttle. after that first run to wot it stuck. i ran it full out while testing with no probs but only for 5-10 seconds at a time. by rich i mean no carbon. just wet looking bare aluminum. are these things usually this tempermental with such mild mods?

  8. #8
    Quote Originally Posted by Hydrotoys View Post
    -Water ingestion would be my first guess.
    -Pressure test the engine. Could have a blown rear seal.
    -Cylinder base gasket on 180deg out (but the other two would be bad.)
    -Injector issue or someother FI issue.
    engine held 10 psi no leaks. i would think a bad injector would cause a poor running condition. it ran great until it stuck.

  9. #9
    Quote Originally Posted by rotax racing View Post
    it has a free flow exhaust and a riva flame arrestor(no outerwear). he rode around for about 45 min varying the throttle. after that first run to wot it stuck. i ran it full out while testing with no probs but only for 5-10 seconds at a time. by rich i mean no carbon. just wet looking bare aluminum. are these things usually this tempermental with such mild mods?
    Not that temperamental.

  10. #10
    Quote Originally Posted by Hydrotoys View Post
    Did you have the rear cylinder re-nikisil'd or just replaced it with a new one?
    the jug lived through the first seizure. cleaned it up with muriatic acid. got lucky. not so sure second time around.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Attn: Jerry
    By Alex13 in forum 4-Tec Performance
    Replies: 1
    Last Post: 07-26-2006, 06:49 PM
  2. Attn: Jerry or Shibby
    By BertInTexas in forum 4-Tec Performance
    Replies: 12
    Last Post: 07-25-2006, 03:15 PM
  3. ATTN Rapid!!!!!!
    By PiMPNXP in forum Sea Doo Open Discussion
    Replies: 1
    Last Post: 04-21-2006, 07:26 AM
  4. ATTN: All Mid-Northern East Coast PWCers! READ :)
    By Shibby1485 in forum Sea Doo Open Discussion
    Replies: 13
    Last Post: 12-19-2005, 10:05 AM
  5. ATTN:Jet Ski Lovers
    By Insanediego Joe in forum Yamaha Open Discussion
    Replies: 0
    Last Post: 10-05-2005, 10:33 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
  •