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Thread: 1999 Gp 1200

  1. #1

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    1999 Gp 1200

    Hey Guys ,I have another issue with my 99 gp 1200.Took it out Yesterday when i first started it on the trailer before putting it in the water it was back firing around 4000 rpms.Once i launched it and fired it up ,went to take off and it wanted to fall on its face. After a few minutes of putting around at idle she was ready to go and ran fine.After about an hour on the water of harder riding it seems like it was braking up and losing speed then about half an hour after that it really started to break up like the it was running out of gas (Had about 3/4 tank at this point) Example Cruising at 55 and it would just cut back to 50 and out of know where just take off again almost like there is some kind of rev limiter or the best why for me to describe ,like its dropping a coil Any Ideas??????

    Forgot to mention that last week the starter just keep clicking when i got to the docks ,then finally started and has been fine .I cleaned the connection last week when i got back ,but really dont know if that was the starter problem or not.


    Compression 118 all three
    carbs redone a few months ago
    Tank completely cleaned out a few months ago (GAS)
    new plugs 2 weeks ago

    All these things were done as a maintenance, not because of the problem at hand

    The only other thing i forgot to mention is when i took it out of the water and pulled the seat off i noticed that 1 and 2 plug wires were not snap in all the way and 1 , the top of the spark plug was bent .It was weird i really dont know what happened there but the boots were on .Once i put them back on there was different in they way it ran


  2. #2
    its possible that while u were jumpin round out there that the lead end was comming away from the plug?..

    bent end on the plug is no good either.

    i had a simular problem.. (intermitant lack of power) on one outing.. and i had not clicked the leads on to my plugs and they were just jumping up and down on the plugs. hopfully its somthing easy like that!

    also if you had a problem with the connection on the starter (corrosion?) pop the lid off the electrical box and make sure theres no corosion in there i guess.

  3. #3

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    Thanks Moo i did put the wires back on and check the connection ,Started it today and it still is back firing.Does anyone know how to check the timing on this ski as far as ,Stator,cdi and coils

  4. #4
    Nickeljet's Avatar
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    Have you changed the plugs?

  5. #5
    Moderator OsideBill's Avatar
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    Backfiring can be caused by an air leak or lean condition.

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  7. #7

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    I Changed the plugs today.

    Osidebill: Im starting to think the same thing .One thing we did today as well was to check the plug wires and we noticed that the ends were very brittle,after taking the boot of the tip of the wires just feel off in are hands .We decide to cut them back a bit and reattach the boots (On the plug side)With that being said we proceeded to fire her up and she did run better but still had a slight surge at idle,did not notice the backfire but the arrestor was back on at this point .I forgot to mention that with the stock flame arestor off we can see it backfiring though the carbs (Maybe Reeds?? )I live in South Florida so in the morning its supposed to be around 75 to 84 so i will be on the water early to try her out and see if there is any change .I will report back tomorrow .Thanks guys

  8. #8

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    One more thing .Where are this 1200's prone the having air leaks ????

  9. #9
    from what iv been told.. if its been popping then check ur crank seals as the backfiring can blow them off the seats. also did you do the check valves when u dd the carbs?

  10. #10

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    Yes did the check valves,as for the crank seals as far as the front is concerned it is not leaking ,I pulled the flywheel off and checked it it out because i thought maybe it was bad ,but no indication of that being a problem

    Ok so today i took her back on the water and i still have the same issues ,im starting to think maybe that the carbs have something to do with it ONLY because there is a bog involved and the ski is using a ton of gas.It just feels to me like its running out of gas when you are on full throttle ,again it doesnt do it all the time i rode it today for about 1/2 hour before it did it once then it did it maybe 5 more times in the next half hour .This ski is using too much gas to the tune of 3/4 of a tank in about 45 mins.

    Any Suggestions ??????????

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