Results 1 to 19 of 19
  1. #1
    Junior Member
    Join Date
    Jun 2011
    Location
    Decatur, MS
    Posts
    7
    Watercrafts
    1997 SeaDoo Bombardier XP with Rotax 787 engine
    Thumbs Up
    Received: 0 Given: 0


    Default Ignition Issue on a 1997 XP with a 787 Rotax

    The engine turns over fine. Good spark coming from plugs. Gap set to .024". Sprayed fresh gas in each carb. Will not try to start. Plugs have wet fuel on them when removed. Checked compression of each cylinder (125 psi each). What is the probability of a sheared keyway on the flywheel? Is there anything else to check? Any help is greatly appreciated...Thanks!

    0 Not allowed!

  2. # ADS
     

  3. #2
    Dr Honda's Avatar
    Join Date
    Apr 2009
    Location
    Pittsburgh
    Posts
    15,989
    Watercrafts
    '00 Polaris Genesis '96 XP800 '02 Islandia 240 EFI
    Thumbs Up
    Received: 169 Given: 0


    Default

    It's very unlikely that the flywheel has moved. It doesn't happen very often with seadoo. It's more likely that the gears in the rotary valve have given out. Also.. 125 PSI is too low on an 800 engine. That engine should be at 150 ~ 155 psi.


    By any chance did you convert to premix?
    Last edited by Dr Honda; 06-13-11 at 09:29 PM.
    Tony
    Prez, A&L Motorsports, LLC
    PM or post for help. Don't leave questions in my profile box. (i never check it)

    I'm not going to be able to do vinyl or carbs for a while. Starting my new job is taking a lot of time

    0 Not allowed!

  4. #3
    SeadooForum Pro purple_people_eater's Avatar
    Join Date
    Aug 2010
    Location
    Western NC
    Posts
    1,168
    Watercrafts
    1996 XP 2009 rxt is 255 2009 gtx wake 155 1989 ranger 371v
    Thumbs Up
    Received: 22 Given: 0


    Default

    check the coil in the rear e-box. make sure all conections are tight. use a test light to see if you have power to the white wire at the coil. if you do not have power there open up the mag housing on the front of your motor and inpect your pick-up coil.
    Scott -Owner WC2- "Tech" leader-The X4 Thread/Cult/Check out The X4 Thread

    0 Not allowed!

  5. #4
    Junior Member
    Join Date
    Jun 2011
    Location
    Decatur, MS
    Posts
    7
    Watercrafts
    1997 SeaDoo Bombardier XP with Rotax 787 engine
    Thumbs Up
    Received: 0 Given: 0


    Default

    I have not converted to premix yet. I do intend on doing this soon. You mentioned an 800 engine. Is this the same as the 787? I will pull the carbs and check the rotary valve. Do you know of a specific test I can do to verify?
    I appreciate the quick response...

    0 Not allowed!

  6. #5
    Dr Honda's Avatar
    Join Date
    Apr 2009
    Location
    Pittsburgh
    Posts
    15,989
    Watercrafts
    '00 Polaris Genesis '96 XP800 '02 Islandia 240 EFI
    Thumbs Up
    Received: 169 Given: 0


    Default

    Yep... the 787 = 800 in the seadoo world.

    No real test... just crank the engine. You should see the valve rolling smooth.

    0 Not allowed!

  7. #6
    Junior Member
    Join Date
    Jun 2011
    Location
    Decatur, MS
    Posts
    7
    Watercrafts
    1997 SeaDoo Bombardier XP with Rotax 787 engine
    Thumbs Up
    Received: 0 Given: 0


    Default

    I do have power on the coil primary. I also pulled the magneto cover and cleaned the trigger coil and stator. All looked good. I verified the resistance of the trigger coil as well. I have a good visible / audible spark at plugs. It did backfire once.

    0 Not allowed!

  8. #7
    Junior Member
    Join Date
    Jun 2011
    Location
    Decatur, MS
    Posts
    7
    Watercrafts
    1997 SeaDoo Bombardier XP with Rotax 787 engine
    Thumbs Up
    Received: 0 Given: 0


    Default

    I pulled the carbs and cranked the engine. The rotary valve turns smoothly. I measured the gap and it is .010" like the book specified.

    0 Not allowed!

  9. #8
    Dr Honda's Avatar
    Join Date
    Apr 2009
    Location
    Pittsburgh
    Posts
    15,989
    Watercrafts
    '00 Polaris Genesis '96 XP800 '02 Islandia 240 EFI
    Thumbs Up
    Received: 169 Given: 0


    Default

    Well... sounds like it should at least start.

    I would hit it with some starter fluid, and see what happens. BUT... as I said above... 125 psi is too low... and even if it starts, it won't run well in the water.

    0 Not allowed!

  10. #9
    Junior Member
    Join Date
    Jun 2011
    Location
    Decatur, MS
    Posts
    7
    Watercrafts
    1997 SeaDoo Bombardier XP with Rotax 787 engine
    Thumbs Up
    Received: 0 Given: 0


    Default

    It will turn over and will usually give one large backfire. I pulled the rotary valve cover to inspect timing. It rotates smoothly with no scarring or real signs of wear. Appears to be in good condition. I rechecked compression. I am getting 125 on the mag side cylinder, and 145 on the other.
    Summary, new plugs B8ES, new fuel, verified trigger coil, ignition coil, rotary valve condition and timing. I also placed rods on both pistons, at no time during the cycle did the two move in the same direction. I feel very confused...I have fire, fuel, air, and timing appears to be correct. What am I missing??

    Thank you all for your suggestions. I am learning more with every post...

    0 Not allowed!

  11. #10
    SeadooForum Pro ski-d00's Avatar
    Join Date
    Apr 2009
    Location
    St. Marys, Ohio
    Posts
    1,502
    Watercrafts
    2008 GTX LTD 2008 RXPX 2006 3D DI 2005 Speedster 200 SC 370HP
    Thumbs Up
    Received: 37 Given: 0


    Default

    you said you checked the rotary valve timing but did you check electrical timing with a dc timing light? simple to check.

    if you have compression, fuel, and well timed spark, it will fire.

    0 Not allowed!

  12. #11
    Experienced Rider 6KJR's Avatar
    Join Date
    Aug 2008
    Location
    ON, Canada
    Posts
    531
    Watercrafts
    1997 SPX
    Thumbs Up
    Received: 0 Given: 0


    Default

    Quote Originally Posted by Dr Honda View Post
    Well... sounds like it should at least start.

    I would hit it with some starter fluid, and see what happens. BUT... as I said above... 125 psi is too low... and even if it starts, it won't run well in the water.
    Im shocked to hear you suggest that!

    Check the plug that goes into the mag as well, Ive seen some of those posts get burned up before. Youll need a little mirror.

    0 Not allowed!

  13. #12
    Junior Member
    Join Date
    Jun 2011
    Location
    Decatur, MS
    Posts
    7
    Watercrafts
    1997 SeaDoo Bombardier XP with Rotax 787 engine
    Thumbs Up
    Received: 0 Given: 0


    Default

    I believe I am getting closer to the problem. I have two questions though. First, how do I test the trigger coil other than resistance? It reads 245 ohms which is within the specs in the manual. What voltage should I be reading at the primary of the ignition coil? I am still not getting a consistent spark when reading with a timing light as ski-doo has suggested. Thanks again for the continued help! It is very appreciated...

    0 Not allowed!

  14. #13
    Experienced Rider KyleB's Avatar
    Join Date
    May 2011
    Location
    Alabama
    Posts
    405
    Watercrafts
    1957 Arkansas Traveler row boat 1999 Caravelle 209BR 1996 Seadoo XP
    Thumbs Up
    Received: 2 Given: 0


    Default

    I'm interested to see what the problem winds up being because I am having the same problem with my 96 XP and I'm in the process of rebuilding the carbs. The responses that I got when I initially posed my question has be wildly different than some of these.

    Kyle

    0 Not allowed!

  15. #14
    Member
    Join Date
    Oct 2011
    Location
    Philadelphia
    Posts
    52
    Watercrafts
    '97 seadoo xp 787
    Thumbs Up
    Received: 0 Given: 0


    Default questions

    I have a 97' xp and im rebuilding the 787. at first it was just a piston problem (compression 90 and the other is 152) which i removed while the engine was still in but then i noticed the rod was moving up n down slightly so i pulled the engine and am in the process of taking the bottom end off. I have all the bolts out except for the one that the starter to flywheel housing is in the way of. So now i have to remove the flywheel and thats where im lost. the ignition cover is off but idk if i should remove the magneto flywheel cause isnt that the timing. From just looking at it i think the flywheel with the magneto flywheel just spin off. Also idk where to find the repair manual. iv been doing everything by just looking at it. Any help would greatly be appreciated. thanks

    0 Not allowed!

  16. #15
    Seadoobuddy's Avatar
    Join Date
    Jul 2011
    Location
    White Lake Township, Michigan, also some in Bradenton, Florida
    Posts
    6,481
    Watercrafts
    96 GTX , 99 GSX Limited, 19 ft. Glastron I/O boat.
    Thumbs Up
    Received: 77 Given: 18


    Default

    RP18 - Welcome to the forum.
    You should really start a new thread with your problem, it will get more replies that way.

    If you become a premium member you can download the manuals for free and get faster response time to your questions from the experts here.

    Rebuilding help I can't give.

    0 Not allowed!

  17. #16
    SeadooForum Hall of fame ocod's Avatar
    Join Date
    Jun 2010
    Location
    Miami
    Posts
    3,172
    Watercrafts
    2006 Yamaha VX Deluxe // 2005 Yamaha VX
    Thumbs Up
    Received: 25 Given: 2


    Default

    Hello, and welcome.
    Its better to start you own thread to get the best help.
    If you google seadoo manual its the first one for free. Or join site for more personal attention to questions.

    0 Not allowed!

  18. #17
    SeadooForum Pro ski-d00's Avatar
    Join Date
    Apr 2009
    Location
    St. Marys, Ohio
    Posts
    1,502
    Watercrafts
    2008 GTX LTD 2008 RXPX 2006 3D DI 2005 Speedster 200 SC 370HP
    Thumbs Up
    Received: 37 Given: 0


    Default

    you need a special tool to remove the flywheel, it doesn't just spin off. it is pressed onto a tapered shaft with a keyway. don't try to spin it, you'll do major damage. you absolutely have to have the flywheel puller tool to remove the flywheel. the timing is set by they keyway so that is not a big deal. you do need a manual, you can get it here or a CD on ebay for $5, or other places online for free if you look hard enough.

    0 Not allowed!

  19. #18
    Bills86e's Avatar
    Join Date
    Feb 2009
    Location
    TampaBay, Florida
    Posts
    3,105
    Watercrafts
    Sea Doo 95, XP, SPX, GTX, SPI, XP, 97 Polaris Hurricane
    Thumbs Up
    Received: 21 Given: 3


    Default

    The correct plugs are BR8ES gapped .021. Your CDI system needs resistor plugs.

    Bills86e

    0 Not allowed!

  20. #19
    Member
    Join Date
    Oct 2011
    Location
    Philadelphia
    Posts
    52
    Watercrafts
    '97 seadoo xp 787
    Thumbs Up
    Received: 0 Given: 0


    Basic Post thank you

    Quote Originally Posted by ski-d00 View Post
    you need a special tool to remove the flywheel, it doesn't just spin off. it is pressed onto a tapered shaft with a keyway. don't try to spin it, you'll do major damage. you absolutely have to have the flywheel puller tool to remove the flywheel. the timing is set by they keyway so that is not a big deal. you do need a manual, you can get it here or a CD on ebay for $5, or other places online for free if you look hard enough.
    thank you. ill have to buy that. I will start a new thread if i have any more questions. thanks for the quick response everyone

    0 Not allowed!

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. 1997 gtx rotax problem
    By merrick in forum 2-Stroke Sea-Doo PWC forum
    Replies: 0
    Last Post: 05-13-11, 05:21 PM
  2. twin rotax Marine charging issue
    By tvallejo in forum 2-Stroke SeaDoo Sport Boat Forum
    Replies: 1
    Last Post: 05-09-11, 03:33 PM
  3. year 2000 bombardier 14.5' twin 85hp rotax idle issue
    By nitrider in forum 2-Stroke Sea-Doo PWC forum
    Replies: 3
    Last Post: 03-16-11, 04:56 PM
  4. year 2000 bombardier 14.5' twin 85hp rotax idle issue
    By nitrider in forum 2-Stroke SeaDoo Sport Boat Forum
    Replies: 1
    Last Post: 03-16-11, 09:17 AM
  5. 1997 XP R.A.V.E questions.. (rotax 787)
    By SheaMolt in forum 2-Stroke Sea-Doo PWC forum
    Replies: 3
    Last Post: 06-07-09, 12:33 AM

Members who have read this thread : 9

You do not have permission to view the list of names.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Register forum what's new