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  1. #1

    97 GP760 has a new owner...maybe needs new plug wires?

    Had a lightly breathed on '95 Waverunner III GP and a '93 SuperJet back in the day (before kids). Kids are finally old enough to be in the water without Mom freakin', so I started looking again.

    First off, couldn't believe how expensive they were...then I couldn't believe how heavy they had gotten. No wonder you need a turbocharged R1 motor to make the thing move

    Then I started trying to figure out how the heck you'd maintain 'em. My two stroke twins were trouble free for years, barring a plug change or two

    So when I saw a seventy-one hour '97 GP760 for a fair price, it was time. It was clean, almost as clean as my old boats were when I sold 'em. First time in the water, I was pretty happy. Little miss between and a soft spot between 3000-4000 RPM, but keep the throttle steady and eventually it would work though it and hit at about 5000 or so, and when it hit it was a lot more motor than my old GPIII ever had, even after the Riva pipe. Figured it was just plugs.

    Pulled 'em, the front was wet, the back didn't look all that bad. Figured the previous owner had just been idling it too much lately.

    Second time in the water, after about five minutes, the soft spot is back. Shortly after that, I notice that my brother-in-law is sitting still in the lake, for a long, long time. Then a stroke Honda tows him in. Just to make it worse.

    Check the plugs, not that bad, front's dry even, but it won't start. Spins, appears to be getting gas, but I don't see any spark.

    So, it's going in the shop Tuesday, as I've kinda exhausted my troubleshooting ability (never was much of a diagnostic wrencher).

    But more and more I'm wondering if it isn't just bad plug wires? Kinda makes sense...doesn't it?

    Anyway, sorry about War and Peace, but anyone have any ideas? Any common problems with the 760s that sounds like this?
    Last edited by ChirpOnYou; 07-12-2010 at 02:59 PM. Reason: Better reflect main thought of thread

  2. #2
    Join Date
    Apr 2006
    Orange, TX
    The plug wires get brittle and break off at the ends where they connect to the plug cap, due to vibration and age. Pull the cap off and trim the insulation of the plug wire back atleast an 1/8" or until you get to some good wire. Its either this or the ignition coil.

  3. #3
    krispaintballz's Avatar
    Join Date
    Sep 2007
    Kenosha, WI
    Quote Originally Posted by 97GPSLEEPER View Post
    The plug wires get brittle and break off at the ends where they connect to the plug cap, due to vibration and age. Pull the cap off and trim the insulation of the plug wire back atleast an 1/8" or until you get to some good wire. Its either this or the ignition coil.

  4. #4

    Join Date
    Jun 2010
    GTA , Canada
    Hey Im going to have a thorough inspection of my wire ends too. Im having a strange issue with my gp and im suspecting ignition.

    Thanks for the replies guys this might help me too.


  5. #5

    Join Date
    Nov 2009
    In addition, make sure you use the new, blue Stabil gas treatment. My GP760 ran great the first couple times out, then wouldn't start. Tried new plugs, no luck. Added blue Stabil, sloshed it around, and the ski fired right up. Get an extended ride plate to counteract the porpoising, change out intake grate while your down there, and you're set. All the guys here will tell you it's a pretty bulletproof motor.

  6. #6
    Yeah, I'd hoped it would be as trouble-free as the 701s I had... Getting off to a bad start.

    So after $200 bucks at the dealer, I had new spark plugs and some kind of story about air bubbles in the fuel lines. They did mention a 'pinhole" leak in the exhaust coupler that was leaking water into the hull, and that I should probably take care of that pretty soon.

    When I got there, I told them that the fouled plugs had about 20 minutes of run time on them. "Oh" was the comment. Then he said they they only ran it on the hose, and not in a tank, and the leak may be bad enough that it's also putting exhaust into the hull, which may be the cause of all my tribbles.

    That sounds plausible, as I had a similar problem one on my GP III when the Riva came loose once. I'll be looking forward to putting it in the water when I get it back, and I'm thinking that if that doesn't solve it I'm done with my favorite local dealer.

    While searching for a second ski I found an old skool shop down in Dripping Springs. Gotta love a place with a back yard full of hulls and benches with motors and carbs everywhere. They also have an Kawi Ultra 150 for sale

  7. #7

    Join Date
    Jun 2010
    GTA , Canada
    I had the exact problem mentioned above. BAD wire ends i couldnt believe it ran the way it did. I took off about a half inch and now it runs GREAT. Thanks Guys!

  8. #8
    Here come the smokers! OBXJeepGuy's Avatar
    Join Date
    Aug 2008
    Outer Banks, NC
    My wires were bad enough last year that I had to send the coil in to JSS, and had the wires replaced. Worked like magic!

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