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  1. #1

    SHO engine surging between 6500 and 7500 rpms

    Hi All

    I pciked up a 2011 FX SHO a couple of weeks ago and had a couple of niggles with it, hope you guys can shed some light on this one.
    While at WOT for almost a minute the ski dropped its revs to 6500 rpm (from 7500) then in a couple of secs its surges back to 7500 rpm. Makes the Ski buck a bit as it gets in this rythem, if I back off a bit and go WOT for a short time it seems perfectly fine so only seems to be an issue when pegged at WOT for a period of time. River was like glass so no hookup problems or pump blockages as it seems fine if I back off a little. I had 2 others ride the ski and they did not have the issue, but they said they were only at WOT for less than 20 seconds so I don' think its a fair test.
    Engine seemed to sound ok, but very hard to tell at over 60mph and the ski is performing very well apart from the couple of times at sustained wot. I thought it might be a fuel starvation problem or maybe the engine is getting too hot and it drops back a bit. I read some other threads regarding a thottle sensor which could be an issue.
    No engine lights or alarms and the ski is bone stock.

    Any thoughts would be much appreciated.

    Thanks

    Dave
    FX HO and FX SHO


  2. #2
    Ale's Avatar
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    strange issue.
    never had on mine.
    with no dash alarm I think it cound not be ECU limitation.
    stock ski don't have overheat problem on long wot ride.
    but if something block water inlet, ski overheat and you see dash alarm.
    without alarm on dash... I have no idea.
    only one time my ski dropped down from 8000 to 7000.....
    was because my engine blown...

  3. #3
    Quote Originally Posted by Ale View Post
    strange issue.
    never had on mine.
    with no dash alarm I think it cound not be ECU limitation.
    stock ski don't have overheat problem on long wot ride.
    but if something block water inlet, ski overheat and you see dash alarm.
    without alarm on dash... I have no idea.
    only one time my ski dropped down from 8000 to 7000.....
    was because my engine blown...
    Thanks Ale

    Does not seem to big an issue, we finished riding as normal. Just a bit cautious as its a new purchased.


    Dave

  4. #4
    ksalles's Avatar
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    How long did the ski sit and how old is the fuel? I had something similar happen on my SHO that I had purchased for my conversion. If you think this could possibly be an issue, try new fuel and new plugs if you can drain the tank. If not, run it as close to out of fuel as possible, then change the plugs and add fresh fuel.

  5. #5
    Thanks ksalles

    I suspec the ski has sat around a fair bit, probably done only a couple of hours on the water in the last 6 months. I will take your advise and check the plugs tomorrow, I have put 2 full tanks thru it in the last week and will get it out on the water as soon as I can.

    Regards

    Dave

  6. #6
    Pull out your fuel pump, take apart the assembly and clean the fuel filter, pop out the injectors and spray them with carb and choke spray to clean them off...Post results....


    where do you live, is it possible that your inter cooler getting heat soaked and slowing the ski down ?

  7. #7
    THE PLATE MAN JIM'S PERFORMANCE's Avatar
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    Quote Originally Posted by Spi200 View Post
    Hi All

    I pciked up a 2011 FX SHO a couple of weeks ago and had a couple of niggles with it, hope you guys can shed some light on this one.
    While at WOT for almost a minute the ski dropped its revs to 6500 rpm (from 7500) then in a couple of secs its surges back to 7500 rpm. Makes the Ski buck a bit as it gets in this rythem, if I back off a bit and go WOT for a short time it seems perfectly fine so only seems to be an issue when pegged at WOT for a period of time. River was like glass so no hookup problems or pump blockages as it seems fine if I back off a little. I had 2 others ride the ski and they did not have the issue, but they said they were only at WOT for less than 20 seconds so I don' think its a fair test.
    Engine seemed to sound ok, but very hard to tell at over 60mph and the ski is performing very well apart from the couple of times at sustained wot. I thought it might be a fuel starvation problem or maybe the engine is getting too hot and it drops back a bit. I read some other threads regarding a thottle sensor which could be an issue.
    No engine lights or alarms and the ski is bone stock.

    Any thoughts would be much appreciated.

    Thanks

    Dave
    FX HO and FX SHO
    If you let up just a tad and the problem is not there, you might be on the limiter.
    Last edited by JIM'S PERFORMANCE; 09-18-2014 at 08:27 PM.

  8. #8
    Thanks Guys

    I am in Sydney Australia and temps were only about 72 degree so a little on the cool side. It still could be heat related due to being at WOT for so long, I suspect it maybe fuel starvation of some sort. I will try some injector cleaner and some fuel conditioner as the ski had been sitting around for a long while before I purchased it. Will see how it goes next rip out before I start pulling stuff apart as it was only for 30 seconds out of 3 hours on the water.

    Thanks

    Dave
    FX HO and FX SHO

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