Page 1 of 3 1 2 3 LastLast
Results 1 to 10 of 22

Thread: SL780 No Spark

  1. #1

    SL780 No Spark

    Long time reader - first time caller with problem. While on the lake, had complete shut down. It was quick and definite, felt electrical. Current status: New battery checks out good - MFD was lying but now seems fine after calibration. Start button quite working while checking fuses in electrical box, but tightening the clamp end of a wire fixed that. By the way, the fuses are good. The only thing I hate worse than it not running is not knowing exactly why. Spark plug (out and grounded) does not spark. All lines lead back to electrical box, then to the "black box" within. Is there a test method, or do I just bend over in front of the parts counter? Thanks for any help!


  2. #2
    Click avatar for tech links/info, donation request K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    36,589
    +1
    1,272
    Welcome

    Click below for the service manual, and other useful links.

    The CDI ignition module inside the electrical box can not be tested directly. What you do is check everything connected to the CDI, and process of elimination tells you if the CDI needs to be replaced.

    The good news is that used parts are available for reasonable prices.

    Disconnect the Black/Yellow wire that goes into the CDI module, which is the engine shut down wire from the lanyard.

    If that doesn't allow the engine to spark, then work through the no-spark tests in the manual. Ohm the stator coils, and look carefully for corroded, broken, or loose wire ends.

  3. #3

    Thanks for the welcome

    OK K447, I'm on it. The electrical box is very clean, but a review of all connections would be prudent. With fingers crossed, I will follow your suggested method. Be back soon.
    Thanks, Ward

  4. #4
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
    Join Date
    Oct 2006
    Location
    Cleveland OH
    Posts
    17,330
    +1
    31
    Welcome to the Hulk Ward.



    Ohm test the stator according to the manual.

    Make sure all grounds are clean and tight.

  5. #5

    Test Update

    Hi Guys, Thanks for the assistance. Here are my results: All stator coils tested within range as per manual procedure and specifications. The procedure then sent me to the secondary ignition coil resistance. The first test, after isolating each coil, calls to test Black (GRD) to Black/White (from CDI into coil #1). I was confused as to if this meant ground to CDI output, or ground to coil input lead. It really didn't matter, I recorded no reading to either. I then moved on to test the coil lead to spark plug end. No reading on any of the three! Can all three plug coils go bad at the same time, and if so, what kind of catasphrofic event would cause this - let me guess - CDI implosion? My conclusion is to search for a new CDI and plug wires with coils, but would appreciate the technical input of great minds like yours (flattery). Thanks, Ward

  6. #6
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
    Join Date
    Oct 2006
    Location
    Cleveland OH
    Posts
    17,330
    +1
    31
    Ward, did you test each coil's Black to black/white with an ohmeter?

    And then you ohm the coil to the plug wire without the spark plug boot.

    The plug boot itself can be ohm tested.



    I doubt all 3 coils failed. My bet is your tester wasn't on the correct setting, or you had your wires crossed up during testing..

  7. #7

    Response

    Xlint89: I tested Black/White to each coil lead wire, the wire first entering the coil as fed from the Black/White wire end. As I type this, I realize a problem. By testing wires as described above, on the first coil I am testing 2 wires for resistance that are supposed to be connected. I'm not sure that makes sense. I will review my instructions and attempt it again. There are only three sides to each coil - surely I should fing a reading somewhere. Thanks for the help, it may save my marriage. This is the wifes' ride, custom painted with her college teams colors.

  8. #8
    Click avatar for tech links/info, donation request K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    36,589
    +1
    1,272
    Have you seen this thread, which is linked to from this domestic engine web page?

    How do I test old and new CDI, Magneto and Ignition coils?

  9. #9

    New Update

    Thanks K447 for the last link. It might take a while to sort out the various engine, ignition and CDI types, but I will study it. I just went through everything again. The test procedure calls for testing Black to Black/White - Black to Secondary Lead - Lead Side to Plug Side. There are only 3 lines to the ignition coil. a black lead - a black white lead and a plug wire. If I test B to B/W, what is the test of B to 2ndary lead? I also wonder if I am missing the testing setup, should the coil be totally unplugged, then being a stand alone unit? Anyways, here are my results. B to B/W (coil leads unplugged) gave me readings of 2 with meter set on 1ohm, on all coils. When testing (meter on 1kohm) lead to plud end, #2 and #3 were strong (10), but #1 was dead. I typically woould expect the engine to run very rough on only 2 cylinders, but can this shut down the firing system? Your help is always greatly appreciated. Thanks, Ward

  10. #10
    Click avatar for tech links/info, donation request K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    36,589
    +1
    1,272

    Arrow Fuji 780 engine ohm tests - stator and ignition coils

    Quote Originally Posted by ward View Post
    Thanks K447 for the last link. It might take a while to sort out the various engine, ignition and CDI types, but I will study it.

    I just went through everything again. The test procedure calls for testing Black to Black/White - Black to Secondary Lead - Lead Side to Plug Side. There are only 3 lines to the ignition coil. a black lead - a black white lead and a plug wire. If I test B to B/W, what is the test of B to 2ndary lead?

    I also wonder if I am missing the testing setup, should the coil be totally unplugged, then being a stand alone unit?

    Anyways, here are my results. B to B/W (coil leads unplugged) gave me readings of 2 with meter set on 1ohm, on all coils.

    When testing (meter on 1kohm) lead to plug end, #2 and #3 were strong (10), but #1 was dead.

    I typically would expect the engine to run very rough on only 2 cylinders, but can this shut down the firing system?...
    My error
    I pointed you at the diagnostics for the red domestic engine, but you have a blue Fuji 780 engine.

    What model year is your 780?

    Have you downloaded the service manual?
    Wiring diagrams are in there.

    According to the 1992-1998 Service Manual, the Fuji 780 stator and ignition coil ohms are as follows (1997 780 Fuji engine).
    In most cases, the wires are to be unplugged from everything else when testing a component.

    Magneto stator coils
    Red/Purple to Yellow: 0.6 ohms (Alternator coil - battery charging)
    Red/Purple or Yellow to Black: Infinite/open/no connection
    White/Yellow to Black: 220 ohms (Trigger coil)
    Blue/Red to Red/White: 90 ohms (Pulser coil)
    Red/White to Black: Infinite/open/no connection
    Red/White to Green/Red: 490 ohms (Exciter coil)

    Black stator wire grounding check
    Disconnect the wires from the battery negative, then check Black stator wire ohms to the end of the heavy Black battery wire, and separately to the end of the smaller Black battery wire (if you have one). Both measurements should be under 1.0 ohms, and very close to zero ohms.

    I think there should be zero ohms between the Black ignition coil connection on the CDI to the engine block (with battery negative wires disconnected).

    All
    ground connections must be clean and tight. Grounding is critical to proper operation.


    Side note: As far as I can tell, two of the three ignition coil secondaries are grounded through the other coil primaries to reach the actual black CDI wire and engine ground.
    A rather unusual configuration

    Ignition coils (each)
    Black to Black/White: 0.6 ohms
    Black to Secondary lead: 3.3K-ohms (3,300 ohms)

    Black to Black/White (with all three coils connected in series), but not connected to CDI: 1.8 ohms

    The spark plug caps/boots should measure 5,000 ohms (5.0K-ohms) each.
    Note: For testing low ohms, you must first check your meter offset.
    Short the probes together, and record the reading. Do this again to confirm the reading.

    This is your meter's ohm offset - the amount that the reading differs from the actual ohms.

    When you measure a low ohm coil/wire, record the number.
    Now subtract the offset from the measurement - the result is the actual ohms value of the thing being measured.

    Example: Probes shorted, meter reads 0.4 ohms.
    Probes connected to coil being tested, meter reads 1.1 ohms
    Subtract the 0.4 offset from 1.1 reading gives you 0.7 ohms actual
    1.1 - 0.4 = 0.7 ohms
    Note: Ignition coil primary wires are connected in series.
    If any of the coil primaries is open or shorted, none of the coils may be able to fire the spark plugs.

    All three spark plugs fire together, every time. Three sparks per crank revolution. It does not matter which spark plug/coil connects to which cylinder.
    Exception is the Pro 785 CDI, which fires each spark plug separately.

    Other possible causes of no-spark
    Black/Yellow stop switch may be shorted to ground.

    With Black/Yellow wire to CDI unplugged, do you have spark?
    If yes, then check Black/Yellow wiring and stop switch.

    With lanyard in place, Black/Yellow switch wire to ground should measured open circuit. Lanyard removed, should measure near zero ohms.

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. Replies: 5
    Last Post: 06-13-2016, 06:59 PM
  2. 1996 Polaris SL780 No spark
    By duckdrive in forum Polaris PWC Performance
    Replies: 10
    Last Post: 07-19-2015, 11:29 AM
  3. 1996 polaris sl780 no spark Everything I have tested is good
    By sarah719 in forum Polaris Open Discussion
    Replies: 7
    Last Post: 08-31-2011, 10:49 PM
  4. No spark and water temp alarm
    By ybnormal in forum Yamaha PWC Performance (2-stroke)
    Replies: 4
    Last Post: 08-02-2009, 11:02 AM
  5. Uncovered my GTX today, has no spark.
    By ccassone in forum Sea Doo Open Discussion
    Replies: 33
    Last Post: 03-27-2006, 09:09 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
  •